Diet Coke Can Fondant Cake with Genoise Sponge Cake and Italian Buttercream

This is my daughters college art final.  She had to make an ephemeral art piece (not a permanent piece, it decays over time).  She hates the kitchen and doesn’t bake unless forced to so this was quite the accomplishment for her.  The entire project is made with edible products such as cake (obviously), buttercream (obviously), fondant, pearl dust (for the silver of the can), food coloring gel (for the painting of the words).  Below are the recipes for the cake and the buttercream.  Both are delicious and very easy to make.

Genoise (cake)

This type of cake is very sturdy but also tasty.  It is not moist like a box mix as it is designed to stand up to fondant which is very heavy.  When you layer it with buttercream, however, it takes on a moistness from the buttercream and is wonderful.

9 oz. granulated sugar

12 oz. whole eggs

6 oz. egg yolks

2 oz. butter, melted

1 t. salt

1.5 t. vanilla

9 oz. cake flour, sifted

Preheat the oven to 35o degrees F.  Butter the bottoms and sides of your cake pans and place a piece of parchment paper in the bottom of the pan.

In an electric stand mixer, whip all the eggs and the sugar until increased four times in volume.  This will take a bit – use medium speed and it will take about four to six minutes.  Remove the bowl from the mixer and add the flour and salt, folding it in quickly.  Then fold in the vanilla and butter.  Quickly place the batter into the prepared cake pans and bake for 18 – 24 minutes.  Your cake is done when it springs back when lightly pressed in the center.  Immediately remove from the oven, remove from the pan and allow to cool.  If you are not finishing the same day, wrap tightly in plastic wrap.

Italian Buttercream

8 oz. egg whites

6 oz. water

1 lb. butter, very soft

16 oz. granulated sugar

Combine the water and sugar ( minus 1 T of sugar – reserve) and cook in a sauce pan until it reaches 245 degrees F.  While the sugar and water is cooking, begin beating the egg whites with the remaining 1 T sugar, to the soft peak stage.  After the sugar syrup has reached temperature, slowing drizzle it into the egg whites while whipping on high speed. Whip for about 5 minutes then reduce the speed to medium and whip until the mixture has cooled off.  Switch from the whip attachment to a paddle attachment and gradually add the soft butter, mixing between each addition until it is emulsified.    Use as a filling between layers of cake, frost a cake, as a filling on sandwich cookies, in cream puffs, etc.