After I made all of the sheet cakes and chocolate cake I carved the cakes to create a giant rainbow with 2 clouds on either end. Then I put a thin layer of frosting on the rainbow portion, let dry and separated small amounts of icing, tinted to the colors of the rainbow (ROYGBIV) and hand "painted" the cake. Then I iced the sides of the rainbow white. For the clouds I iced the sides an organized messy to resemble clouds and I used a pastry tip for the tops to make it neater.
Here are the recipes:
Sheet Cakes
Have all the ingredients at room temperature.
2 2/3 Cup sifted Cake flour (I used Presto brand cake flour so I didn't have to add the baking powder or salt - If you use a cake flour without these in it - add 2 1/4 tsp baking powder and 1/2 tsp. salt)
2 sticks butter
1 1/2 Cup Sugar
1 Cup milk
1 1/2 tsp. vanilla extract
4 large eggs separated
1/4 tsp cream of tartar
1/4 Cup sugar
Preheat the oven to 350. Grease a 12X17 sheet pan and line with parchment paper and then grease again. Set aside.
Combine the milk and vanilla in a measuring cup and set aside.
Using a paddle attachment (if you have one - if not just use regular beaters). Beat the butter for about 2 minutes until creamy. Gradually add 1 1/2 Cup sugar to the butter beating on high for about 4 minutes until light and fluffy.
Add the egg yolks one a time mixing until well blended on low speed.
Add the flour in 3 parts alternating with the milk in 2 parts beating on low speed until smooth. On the 2nd addition of the milk add food coloring (I have food color paste that really makes it a deeper shade).
In a separate bowl using the whisk attachment - beat the egg whites and cream of tartar until soft peaks form. Gradually add the 1/4 cup sugar until stiff but not dry peaks form (about 1-2 minutes on high speed). Fold 1/3 of this mixture to the flour/egg yolk mixture, then fold in the remaining whites.
Spread evenly in the pan and bake for 18 minutes or until toothpick comes out clean.
Repeat 4 times (I told you I went overboard) using diffferent food coloring each time. I did red, yellow, green and blue.
This takes about 25-30 minutes to prepare. I started baking these at 10:30 and finished around 2:30.
Devils Food Cake - (This was one of the clouds)
Have all ingredients at room temperature.
Preheat oven to 350.
Grease and line with parchment paper - 2 - 8 inch round cake pans.
Place the following into a double boiler and melt until smooth:
4 ounces unsweetend chocolate - chopped
1/2 Cup milk
1 Cup packed dark brown sugar
1 Large egg yolk
Remove from heat and let cool to room temperature.
Get ready and set aside:
2 Cups sifted cake flour (same instructions for cake flour as with the sheet cake but with 1 tsp baking soda and 1/2 tsp salt)
In a measuring cup combine:
1/2 Cup milk
1/4 cup water
1 tsp vanilla
Using a paddle attachment, beat 1 stick of butter until creamy. Gradually add 1 cup sugar.
Divide 2 eggs - reserving the whites. Beat in yolks one at a time until well combined.
Add the flour in 3 parts to the butter mixture alternating with the milk mixture in 2 parts beating until smooth. Stir in the chocolate mixture.
Using a whisk attachment and clean bowl - beat on high speed the egg whites until stiff but not dry. Fold lightly into the batter.
Divide into the pans and bake for 30-35 minutes or until toothpick comes out clean.
Cool completely.
Frosting for the Clouds - (this actually only made enough to ice one cloud and I didn't have enough time to make more so I made some whipped cream (1 cup heavy cream and 4 T agave) and used it to ice the other cloud)
4 large egg whites
1 1/2 cups sugar
1/2 tsp cream of tartar
1 pinch salt
1 tsp vanilla (I ran out and actually didn't add this but I would have)
1-3 drops light blue color paste (just enough to tint it a pale blue)
In a saucepan bring a few inches of water to a boil. Almost like a double boiler, but you want the bowl you mix the ingredients in to be able to actually fit in the water.
Whisk all the ingredients (except the food coloring) in a bowl by hand. Set the bowl above/in the boiling water and continue to whisk until the mixture is hot to the touch and the sugar dissolves about 1-2 minutes. Be sure not to cook the eggs. Transfer the mixture to a standing mixer fitted with the whisk attachment and beat at high speed until eggs beat up to a stiff meringue adding the food paste about halfway though.
Frosting for the rainbow part
2 1/2 Sticks butter - room temp
5 Cups confectioners sugar
2 Tbsp Milk
1 Tbsp vanilla
Mix all together until smooth.