Instructions for White Cake:
Preheat the oven to 350 F. Beat eggs and sugar together on high in the mixer bowl, for 10 minutes. (I use Professional 6000 HD Kitchen Aid Mixer. If you are working with a hand mixer, it will take much longer to beat the eggs and sugar into the necessary thick and stiff consistency.) Sift in the flour, mixed with baking powder, and then fold it over the very gently with a whisk or spatula not to deflate too many air bubbles.
Pour batter into a greased 8” square pan lined with parchment paper. Bake at 350 F for 25 minutes. Let it cool in the pan for 5 minutes before taking it out of the pan.
Instructions for Chocolate Cake:
Beat eggs and sugar on high in the mixer bowl for 10 minutes. Combine flour, baking powder, and cocoa in a bowl. Sift in half of the dry ingredients and gently fold into the egg mixture. Be careful not to deflate many air bubbles. Then sift in the other half of dry ingredients and repeat the same gentle mix.
Pour batter into a greased 8” square pan lined with parchment paper. Bake at 350 F for 30 minutes. Let it cool in the pan for 5 minutes before removing it from the pan
Inner Cream Instructions:
Beat sour cream and softened cream cheese for a minute. Add sugar; beat for another minute or until all sugar is dissolved. Add cool whip and beat for 2 minutes. Scrape down the sides of the bowl and beat for 3 minutes. Set aside until ready for use.
Assembling the Cake:
Cut each cake sponge in half. (I precut the edges with a knife and then insert a thread and with a side to side motion, cut through the whole sponge and finish when the thread is freed on the opposite side. See images and instructions on how to perfectly cut a cake sponge horizontally in Curly Boy Cake.)
Place a white sponge layer on a cake holder. Spread ¼ of the cream over sponge evenly. Then place a chocolate layer on top of the cream and then spread another ¼ of the cream. Repeat these steps until the rest of the sponges are assembled.
With the remaining ¼ of the cream crumb coat the top of the cake. Place it in the fridge to set a little before decorating, about 1 hour.
Outer Cream Instructions: I use the same Cream as for the Honey Chocolate and Strawberry Cake. Split the cream between 3 small bowls and add Wilton gel food coloring. Beat each cream well, scraping down the sides of the bowl periodically.
Decorating the Cake:
Remove the cake from the fridge and spread half of the sky blue cream on top and half way on the sides of the cake evenly.
Transfer the rest of the cream 3 separate piping bags and use Wilton 70 tip to pipe out continuous ribbon-shaped folded strips all around the cake.
I placed 2 different cars on top of the cake and then wrote “Happy Bday!” to finish off the cake, but you may choose any decorations and colors you wish. We sliced big pieces of the cake for the bday boys underneath the car they chose. They really ENJOYED their cake, and I think you will as well!