Instructions

CAKE

1. Adjust an oven rack to the center position and heat oven to 325 degrees. Spray 3 8-inch round cake pans with nonstick baking spray and set aside.
   
2. In the bowl of a stand mixer, with the paddle attachment attached, add the cake flour, sugar, baking powder, and salt and mix on low speed to combine.
   
3. Add the butter one tablespoon at a time to the mixer bowl, beating on low speed until all the butter has been incorporated, about 1 to 2 minutes.
   
4. In a 4 cup liquid measuring cup, add the egg whites, vanilla extract, buttermilk and sour cream and whisk to combine.
   
5. Add half of the buttermilk mixture into the mixer bowl and beat on medium-high speed for 1 minute. Add the remaining buttermilk mixture and beat on low speed for about 30 seconds until combined.
   
6. Divide the cake batter between the prepared cake pans and bake for 20 to 25 minutes (rotate cake pans a little over halfway through baking), or until a toothpick inserted in the center of each cake comes out with a few moist crumbs attached.
   
7. Let cakes cool in their pans for 15 minutes, then invert them onto cooling racks to cool completely.

PASTRY CREAM

1. In a medium saucepan, add half-and-half, 6 tablespoons of sugar, vanilla bean seeds and salt to a simmer over medium-high heat, stirring occasionally.
2. Meanwhile, combined the egg yolks, cornstarch and remaining 2 tablespoons sugar in a bowl and whisk until smooth.
3. Whisk in about 1 cup of the half-and-half mixture into the yolk mixture to temper. Slowly whisk in the tempered egg mixture into remaining half-and-half mixture. Reduce the heat to medium and continue to cook, whisking constantly, until the pastry cream is thick and bubbles start to pop on the surface, about 30 seconds.
4. Remove from the heat and remove the vanilla bean and whisk in the butter. Transfer the pastry cream to a bowl and press plastic wrap directly on the surface of the cream. Refrigerate until set, about 3 hours or up to 2 days.
   

FROSTING

1. In the bowl of a stand mixer with the paddle attachment attached, beat the butter, shortening and salt on medium speed until light and fluffy, about 8 minutes. Add the powdered sugar, heavy cream, vanilla and almond extract and slowly mix until combined, about 1 minute.
2. Increase the mixer speed to medium-high and beat until light and fluffy, about 6 minutes. Add pink gel food coloring and mix on low speed until combined.
   

ASSEMBLE

1. Center one cake layer on an 8-inch round cake board and place on a cake turntable with a nonslip mat. Fit a piping bag with a coupler and fill with frosting. Pipe a frosting dam around the edge of the cake. Fill with about 2/3 cup pastry cream and place the second cake layer on top. Pipe another frosting dam around the edge of the cake and fill with another 2/3 cup pastry filling. Place the last cake layer on top, bottom side up.
   

CRUMB COAT

1. Apply a light coating of frosting over the top and sides of the cake to seal in any loose cake crumbs. Freeze the cake for 15 minutes or refrigerate for 30 minutes.

DECORATE

1. Apply a generous amount of frosting to the top of the cake and slowly work down to the sides of the cake to cover. Use the back of a spoon to give the frosting some texture by pressing the spoon into the frosting and twirl as you lift away. Top the cake with rainbow sprinkles. Transfer the cake to a cake pedestal and serve.