Preheat oven to 335℉. Prepare three 8" round cake pans. I prefer to use cake goop.
Add all of your ingredients into the bowl of your stand mixer with the paddle attachment attached and mix on low for 2 minutes to combine.
Stop and scrape the bowl and then mix on medium for two minutes.
Pour batter into your cake pans and bake for 25-30 minutes until a toothpick comes out of the center with just a few sticky crumbs clinging to the toothpick. I gently touch the top of the cake to see if it bounces back to check if it's done. If it needs more time only bake for 1 minute more then check again.
Let cool a few minutes in the pan before turning out onto a cooling rack. Let cool fully and frost.
Easy Swiss Meringue Buttercream
Place egg whites and powdered sugar in a stand mixer bowl. Attach the whisk and combine ingredients on low and then whip on high for 1 minute to dissolve the powdered sugar
Add in your salt and vanilla extract
Add in your butter in chunks and whip with the whisk attachment to combine. It will look curdled at first. This is normal. It will also look pretty yellow. Keep whipping.
If your buttercream looks curdled, remove about ⅓ cup of buttercream and melt it in the microwave for 10-15 seconds until JUST barely melted. Pour it back into the whipping buttercream to bring it all together.
Switch to a paddle attachment and mix on low for 15-20 minutes to make the buttercream very smooth and remove air bubbles. This isn't required but if you want really creamy frosting, you don't want to skip it.