NOTE: It is SUPER IMPORTANT that all the room temperature ingredients listed above are room temperature and not cold or hot.
Make sure to take your strawberry reduction out of the refrigerator 1 hour before making your cake so that it comes to room temperature.
Adjust an oven rack to the middle position and preheat to 350ºF/176ºC.
Grease three 8" cake pans with cake goop or preferred pan release
In a separate medium bowl, whisk together the milk, strawberry reduction, strawberry emulsion, vanilla extract, lemon extract, lemon zest, lemon juice, and pink food coloring.
In a separate medium bowl, whisk together the flour, baking powder, baking soda and salt.
Add room temperature butter to your stand mixer with the paddle attachment and beat at medium speed until smooth and shiny, about 30 seconds.
Gradually sprinkle in the sugar, beat until mixture is fluffy and almost white, about 3-5 minutes.
Add the egg whites one at a time, beating 15 seconds in between. Your mixture should look cohesive at this point. If it looks curdled and broken, your butter or egg whites were too cold.
Mix on low speed and add about a third of the dry ingredients to the batter, followed immediately by about a third of the milk mixture, mix until ingredients are almost incorporated into the batter. Repeat the process 2 more times. When the batter appears blended, stop the mixer and scrape the sides of the bowl with a rubber spatula. If it looks like ice cream, you did it right!
Divide the batter evenly between the prepared pans. Smooth the tops with a rubber spatula.
Bake cakes at 350ºF/176ºC until they feel firm in the center and a toothpick comes out clean or with just a few crumbs on it, about 30-35 minutes.
Place pans on top of a wire rack and let cool for 10 minutes. Then flip your cakes onto the racks and cool completely.
Once cooled, wrap each layer in plastic wrap and refrigerate or freeze before assembling your cake.