Preheat your oven to 350°F. Grease and line two 8-inch round pans with parchment paper.

In a bowl, whisk together 1/3 cup of whole milk, three egg whites, one whole egg, lemon extract, and vanilla bean paste. Set aside.

In another bowl, sift together flour, baking powder, baking soda, salt, and granulated sugar.

Gradually mix in softened butter to the dry ingredients until crumbly. Pour in the remaining whole milk and mix until moistened.

Incorporate the egg mixture in three additions, mixing just until combined.

Pour the batter evenly into prepared pans and bake for 20-25 minutes or until a toothpick comes out clean.

Cool cakes in pans for 10 minutes before transferring to a wire rack to cool completely.

Combine raspberries, sugar, and lemon juice in a saucepan over medium heat. Cook until thickened, about 10-15 minutes.

Remove from heat and let cool.

Whip softened butter in a bowl until creamy. Gradually add powdered sugar, mixing until light and fluffy.

Fold in half of the cooled raspberry compote to make marbled frosting.

Assemble the cake by spreading frosting and raspberry filling between layers, then frost the top and sides.