Inside-Out Neapolitan Layer Cake

INGREDIENTS

3/4 cup

unsalted butter, softened

2 cups

packed dark brown sugar

2 tsp

pure vanilla extract

eggs, at room temperature

1 3/4 cups

all-purpose flour

3/4 cup

unsweetened Dutch-processed cocoa powder

1 1/4 tsp

baking soda

1 tsp

baking powder

1 tsp

kosher salt

1 1/2 cups

buttermilk, at room temperature

1/4 cup

mayonnaise

large fresh egg whites (150 g)

1 1/4 cups

superfine granulated sugar

1 1/2 cups

(3 sticks) unsalted butter, softened, cut into cubes

2 tsp

pure vanilla extract

salt

5 oz

quality bittersweet chocolate

Few drops Strawberry Flavor Oil, or 2 tablespoons (30 ml) strawberry puree

Few drops pink gel colour