This traditional American Boston Cream Pie recipe isn't a pie but two fluffy and moist layers of yellow cake filled with a thick layer of vanilla pastry cream and topped with smooth and shiny ganache! It's named "pie" because the cake layers were originally baked in pie tins!
I’ve had a Boston Cream Donut before, but never really had Boston Cream Pie until I made this recipe. It definitely captures the essence of the donut with the super smooth pastry cream and ganache.
I recommend making the pastry cream first so that it has time to chill, then make the cakes, chill the cakes, and then assemble everything. The cake does need to chill for a minimum of 6 hours to set up, so think ahead! Or if you’re in a rush, you can turn this recipe into Boston cream cupcakes (my personal favorite).
Table of contents
Boston Cream Pie Ingredients
Boston cream pie filling is traditionally made with vanilla pastry cream that tastes similar to a custard or a pudding. It's made with milk, eggs, butter, and vanilla and uses cornstarch to stabilize the mixture. It's cooked on the stove in a pan and is an easy recipe to make.
Boston cream filling is similar to a bavarian cream filling but bavarian cream filling uses gelatin as a stabilizer instead of cornstarch.
The great thing about this yellow cake is that it's a very easy scratch recipe, but if you're new to baking you can always use a boxed cake mix.
Milk: I’m using whole milk for my pastry cream filling, but you can also use almond milk, soy milk, or coconut milk.
Eggs: Egg yolks and an extra egg make for delicious rich pastry cream. Extra egg yolks also bring the “yellow” color to our yellow cake. If you took out the yolks, it would just be a regular vanilla cake, and if you only used the egg whites it would be a white cake.
Butter: Butter is not technically required for pastry cream, but it adds extra creaminess. I like using Plugra, which is a European butter and has 82% of fat.
Vanilla: You can use vanilla extract, paste, or vanilla beans. I like using Nielsen Massey beans when I have them because they give the strongest vanilla flavor, but any vanilla will work!
Cake Flour: It’s important to use cake flour for this recipe. Do not fall for the “just add cornstarch to regular flour” trick. Your cake will look and taste like cornbread because the higher protein in all-purpose flour develops more gluten.
Pro-tip – If you’re in the UK search for Shipton mills soft cake and pastry flour or flour that has a protein level of 9% or less.
Oil: Adding a little bit of oil in addition to the butter adds extra moisture to the cake. I usually use vegetable oil, but canola will work as well.
Chocolate: Semi-sweet or milk chocolate makes for a great ganache drip, and you can use any brand that you like. My favorites are Guittard, Cacao Barry, and Ghirardelli because they come in chocolate chips so you don’t have to chop up the bars.
Heavy cream: If you don’t have any heavy cream, try making water ganache. It works really well for a drip cake!
Tips For Baking Layer Cakes From Scratch (AKA The Science Part)
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I suggest purchasing a kitchen scale if you don't already have one to make the best cake recipes. One cup of cake flour can vary from scoop to scoop depending on how packed the flour is, humidity, and the type of flour, which can ruin your cake recipe. All my cake recipes (except doctored box mixes) use a scale.
Practice Mise en Place (everything in its place) which means you measure everything before you start mixing so you don't accidentally forget something or add any ingredients out of order. I use a set of medium and small pyrex glass bowls I got from goodwill for this and it makes things SO much easier.
Room temperature ingredients are a must. If your milk and eggs are cold (even a little) then they will actually repel the fats in your recipe (butter) and your cake batter will split causing your cake texture to be off or even collapse. Don't worry, warming up your ingredients is really easy, this is how I make my ingredients room temperature in 5 minutes (which is actually a little warmer than room temperature).
If you have never decorated a cake before, you can watch my free step-by-step tutorial on how to decorate your first cake.
How to Make Boston Cream Pie
Making Pastry Cream
- Place the first measurement of your sugar, cornstarch, egg yolks, and the egg in a medium bowl and whisk together until homogeneous.
- Add your milk, second measurement of sugar, and vanilla into a medium saucepan over medium heat and bring it to a simmer. Pro-tip: Adding sugar to the milk helps stop it from burning on the bottom of the pot.
- Temper the yolk mixture by adding about ⅓ of the boiled milk to the eggs while whisking constantly. Bringing the eggs and milk to the same temperature helps to prevent lumps and curdling.
- Pour the entire mixture back into the pot and cook it on medium heat.
- Keep cooking the pastry cream for a few minutes over medium heat until it's thickened. Don’t worry if it starts to get lumpy, you want to have extra thick pastry cream so that it sets in between your cake layers.
- Remove the pot from the heat and strain everything through a sieve into a large bowl to get rid of lumps. You can also emulsify instead if you have an emulsion blender, just be sure to strain it while warm so that it doesn’t break the cornstarch molecules.
- Add in the butter and whisk until homogeneous.
- Place plastic wrap over the pastry cream so that it's touching the surface of the cream. This will help avoid a skin developing on the top. Place it in the fridge to cool completely while you make your cake.
Making Yellow Cake
- Preheat your oven to 350ºF and prepare two, 8-inch cake pans with cake goop or your preferred cake release. Parchment paper isn’t needed with cake goop, but you can use it if you’re nervous about sticking.
- Weigh out all of your ingredients with a food scale and bring the milk, eggs, and butter to room temperature or slightly warm. I like to microwave my milk, place my eggs in a bowl of warm water for 5 minutes, and chop up my butter (microwave a little if needed). This will create a better emulsion and texture for your cake.
- Place half of your milk (5 ounces), vanilla, and oil into a small bowl and set it aside.
- Add your eggs, yolks, and 3 ounces of milk into a separate bowl. Whisk together and set it aside.
- Add your cake flour, sugar, baking powder, baking soda, salt, and butter into the bowl of your stand mixer with the paddle attachment.
- Mix on low speed until the mixture resembles coarse sand. I'm using my KitchenAid mixer, but you can use a hand mixer and a large mixing bowl if you prefer.
- Stream your oil mixture into the dry ingredients while mixing on low speed. Bump the speed up to medium (speed 4 on KitchenAid) and mix for 2 full minutes. Set a timer for this step, this mixing will develop the structure of the cake.
- Now, stream in your egg mixture and mix on low speed until the batter becomes homogeneous. Don’t forget to scrape the bowl!
- Divide your batter into two cake pans. If you are making cupcakes, place 1-2 tablespoons into each cupcake liner. Pro-Tip: Use a scale to weigh the amounts of batter in each cake pan, this will result in more even layers.
- Bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean. (For cupcakes bake for 15-20 minutes.) Your oven temperature may vary, so make sure the center of your cake is set before removing it from the oven.
- Cool the cakes for 10 minutes while still in the pans, then flip them out onto a wire rack to cool. Flash freeze them for about an hour if you want to decorate right away, or wrap them in plastic wrap (while still warm) and freeze them overnight. Pro-Tip: Wrapping your cakes while they’re still warm seals in the moisture of the cake, making it safe to freeze.
Assembling the Boston Cream Pie
- Prepare an 8-inch cake ring with an 8” cake board and wrap the inside of the ring with acetate. Make sure the acetate stretches about 6 inches above your ring and tape it closed. You can also use a springform pan or any ring that matches your cake layer.
- Once your cakes are chilled, trim off the domes so that the layers are even.
- Place the first cake at the bottom of the ring.
- Pour the pastry cream into a piping bag and pipe all of the pastry cream on top of your first cake layer. It should be about ½-inch thick.
- Place your second cake layer on top.
- Place the entire cake in the fridge to chill for a minimum of 6 hours, preferably overnight. Pro-tip: Cover the top of the cake in plastic wrap to keep it from drying out in the fridge.
Making Chocolate Ganache
After your cake has cooled, you’re ready to make the chocolate glaze.
- Pour the chocolate into a glass container that is easy to pour from, and microwave for one minute. You can also heat these in a small saucepan if you prefer.
- Pour the cream into a medium bowl and microwave for one minute.
- Pour the cream over the chocolate and rest for about 5 minutes.
- Whisk together the chocolate and cream until the ganache is smooth and shiny.
- Set the ganache aside for a few minutes while you unmold the cake.
Unmolding and Decorating
- Once your cake has cooled and set up, remove the metal ring and the acetate from your Boston cream pie.
- Pour the ganache on top, allowing some of the chocolate to drip down the sides of the cake.
- Smooth out the top with a spatula and serve!
- This cake will last for about 4 days in the refrigerator, I recommend covering the entire cake in plastic wrap so that it doesn't dry out.
How to make Boston Cream Cupcakes
I highly recommend making this recipe into cupcakes, I almost like Boston cream pie better in cupcake form because of how cute they are!
- Divide the yellow cake batter into cupcake tins, this recipe will make about 24 cupcakes.
- Bake the cupcakes at 350°F for 15-20 minutes or until they’re set on top and cool fully.
- Cut out a hole in the center of the cupcake and set aside the top.
- Fill the center of the cupcake with pastry cream.
- Place the top back onto the cupcake, sealing in the pastry cream.
- Drizzle some of your chocolate ganache on top with a spoon and serve.
FAQ
A Boston cream pie is a cake with a creamy custard filling, so not technically a pie at all. The Boston cream pie was created in the 19th century back when cakes and pies were cooked in the same pie tins. The Boston Cream Pie was proclaimed the official Massachusetts State Dessert on December 12, 1996.
Pastry cream is the traditional filling for Boston cream pie and is a sweet cream made with eggs, sugar, and milk.
Thoroughly mixing the egg, sugar, and cornstarch is the first step to avoiding lumpy pastry cream. The next step is tempering the egg yolks, if you add all of the eggs to your boiling milk, it could cause the eggs to curdle. You want to temper the eggs by slowly adding in the hot milk while mixing, and bring the mixtures to the same temperature before fully incorporating them. If you do happen to curdle your eggs, you can use an immersion blender to get out some of the lumps or strain your pastry cream through a sieve while it’s still warm.
Yes, pastry cream can stay out for a maximum of 4 hours.
You can use a springform pan or any ring that matches your cake layer if you don't have a cake ring. You might be able to use parchment paper instead of acetate but you risk the pastry cream leaking out. If you don't have any of this equipment, I recommend making this recipe into cupcakes or even going freeform without any ring.
Yes, because of the milk and egg-based filling, Boston Cream Pie should be refrigerated until you serve it but can be left at room temperature for up to four hours in a room that is less than 85ºF.
Recipe
Equipment
- 1 Stand mixer or electric mixer
- 2 8" cake pans
- 1 8” cake ring or pan
- 1 Acetate roll or sheets
- 1 Wire rack
- 1 Seive or immersion blender optional
Ingredients
Pastry Cream
- 16 ounces whole milk
- 2.5 ounces granulated sugar
- 1.5 teaspoons vanilla extract
- 3 large egg yolks
- 1 large egg
- 2 ounces unsalted butter
Yellow Cake
- 14 ounces cake flour
- 12 ounces granulated sugar
- 2 teaspoons baking powder
- 1 teaspoon baking soda
- 1 teaspoon salt
- 6 ounces unsalted butter room temperature
- 2 large eggs room temperature
- 3 large egg yolks room temperature
- 8 ounces whole milk room temperature
- 2 ounces vegetable oil
- 1 Tablespoon vanilla extract
Chocolate Ganache
- 4 ounces semi-sweet chocolate
- 4 ounces heavy whipping cream
Instructions
Making the Pastry Cream
- Place the first measurement of your sugar, cornstarch, egg yolks, and the egg in a medium bowl and whisk together until homogeneous.
- Add the milk, second measurement of sugar, and vanilla into a medium-sized saucepan over medium heat and bring it to a simmer. Pro-tip: Adding sugar to the milk helps stop it from burning on the bottom of the pot.
- Temper the yolk mixture by adding about ⅓ of the hot milk to the eggs while whisking constantly. Bringing the eggs and milk to the same temperature helps to prevent lumps and curdling.
- Pour the entire mixture back into the pot and cook it on medium heat while whisking constantly until it's thickened. Don’t worry if it starts to get lumpy, you want to have extra thick pastry cream so that it sets in between your cake layers.
- Remove the pot from the heat and strain everything through a sieve into a large bowl to get rid of the lumps. You can also use an immersion blender. Just be sure to strain it while it's warm so that it doesn’t break the cornstarch molecules and become loose and liquid.
- Add in the butter and whisk it until it's homogeneous.
- Place plastic wrap over the pastry cream so that it's touching the surface of the cream. This will help avoid skin developing on the top. Place it in the fridge to cool completely while you make your cake.
Making the Yellow Cake
- Preheat your oven to 350ºF and prepare two, 8-inch cake pans with cake goop or your preferred cake release. Don’t worry if it starts to get lumpy, you want to have extra thick pastry cream so that it sets in between your cake layers.
- Weigh out all of the ingredients with a food scale and bring the milk, eggs, and butter to room temperature or slightly warm. I like to microwave my milk, place my eggs in a bowl of warm water for 5 minutes, and chop up my butter (microwave a little if needed). This will create a better emulsion and texture for your cake.
- Place about ⅔ of the milk, vanilla, and oil into a small bowl and set it aside.
- Add the eggs, yolks, and the rest of the milk into a separate bowl. Whisk together and set it aside.
- Add the cake flour, sugar, baking powder, baking soda, salt, and butter into the bowl of your stand mixer with the paddle attachment.
- Mix on low speed until the mixture resembles coarse sand. I'm using my Bosch mixer, but you can use a hand mixer and a large mixing bowl if you prefer.
- Stream your oil mixture into the dry ingredients while mixing on low speed. Bump the speed up to medium (speed 4 on kitchen aid) and mix for 2 full minutes. Set a timer for this step, this mixing will develop the structure of the cake.
- Now, stream in the egg mixture and mix on low speed until the batter becomes homogeneous. Don’t forget to scrape the bowl!
- Divide the batter into two 8" cake pans. If you are making cupcakes, place 1-2 tablespoons into each cupcake liner. Pro-Tip: Use a scale to weigh the amounts of batter in each cake pan, this will result in more even layers.
- Bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean. (For cupcakes bake for 15-20 minutes.) Your oven temperature may vary, so make sure the center of your cake is set before removing it from the oven.
- Cool the cakes for 10 minutes while still in the pans, then flip them out onto a wire rack to cool. Flash freeze them for about an hour if you want to decorate right away, or wrap them in plastic wrap (while still warm) and freeze them overnight. Pro-tip: Wrapping your cakes while they’re still warm seals in the moisture of the cake, making it safe to freeze.
Assembling the Boston Cream Pie
- Prepare an 8-inch cake ring with an 8” cake board and wrap the inside of the ring with acetate. Make sure the acetate stretches about 6 inches above your ring and tape it closed. If you don’t have a cake ring or acetate, I recommend making this recipe into cupcakes or just doing it freeform. Be warned that some of the pastry cream might squish out the sides.
- Once your cakes are chilled, trim off the domes so that the layers are even.
- Place the first cake at the bottom of the ring.
- Pour the pastry cream into a piping bag and pipe all of the pastry cream on top of your first cake layer. It should be about ½-inch thick.
- Place your second cake layer on top.
- Place the entire cake in the fridge to chill for a minimum of 6 hours, preferably overnight. Pro-tip: Cover the top of the cake in plastic wrap to keep it from drying out in the fridge.
Making Chocolate Ganache
- Add the chocolate into a glass container that is easy to pour from, and microwave for one minute. You can also heat these in a small saucepan if you prefer.
- Pour the cream into a medium bowl and microwave for one minute.
- Pour the cream over the chocolate and rest for about 5 minutes.
- Whisk together the chocolate and cream until the ganache is smooth and shiny.
- Set the ganache aside for a few minutes while you unmold the cake.
Unmolding and Decorating
- Once the cake has cooled and set up, remove the metal ring and the acetate from the Boston cream pie.
- Pour the ganache on top, allowing some of the chocolate to drip down the sides of the cake.
- Smooth out the top with a spatula and serve! This cake will last for about 4 days in the refrigerator, I recommend covering the entire cake in plastic wrap so that it doesn't dry out.
Video
Notes
- The best investment you can make when you’re getting started with baking is a digital kitchen scale! Weighing your ingredients will help you avoid cake failure. Using a kitchen scale for baking is super easy and gives you the best results every single time.
- Practice Mise en Place (everything in its place). Measure out your ingredients ahead of time and have them ready before you start mixing to reduce the chances of accidentally leaving something out.
- Need more help with making your first cake? Check out my how to decorate your first cake blog post.
- Make sure all of your cold ingredients (e.g. butter, eggs, milk) are at room temperature or a little warm. Why? Because we want to create an emulsion and allow the ingredients to fully mix together.
- Make your own pan release (cake goop!) The best pan release ever!
- Chill your cakes before frosting and filling. You can cover a frosted and chilled cake in fondant if you wish. This cake is also great for stacking!
- You can substitute milk with almond milk, soy, coconut, oat etc for the pastry cream.
- If you don't have acetate or a cake ring you can just stack and layer rustic style.
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