Rainbow Cake

Our friend Jeff celebrated his 42nd birthday in October. There was a huge surprise birthday party for him and I had volunteered to make the cake. His wife said that his favorite flavor is white cake with chocolate icing, and Hubby had the bright - literally - idea of dyeing the cake and turning it into a rainbow cake.

This was a HUGE cake - a 12" square as the base, then tiers of a 10" round, 8" round, 6" round, and 3" round (or...jumbo cupcake on top!)

We used the "Cake Mix From Scratch & Variations" recipe from Allrecipes.com, except that we made 5 batches since we had such a large cake.

The recipes below are for a regular cake (one 9"x13" pan or two 9" rounds).

WHITE CAKE:
INGREDIENTS:
2 1/3 cups all-purpose flour
1 Tbs baking powder
3/4 tsp salt
1 1/2 cups white sugar
1/2 cup shortening
3 egg whites, beaten until soft peaks form
1 cup milk
1 tsp vanilla extract

DIRECTIONS:
In clean bowl, beat egg whites until soft peaks form.

In large bowl, sift together flour, baking powder, salt, and sugar. Cut in shortening until fine crumbs are formed.

Add milk and vanilla. Beat at low speed for 1 minute, then high for 2 minutes, scraping the bowl frequently. Fold in egg whites.

Pour batter into greased and floured pan. Bake in preheated 350º oven for 25 to 30 minutes (may be more or less, depending on the pan size used).

CREDIT: Submitted by "Janet" on Allrecipes.com

CHOCOLATE COOKIE BUTTERCREAM FROSTING:
INGREDIENTS:
1/4 cup butter
2 cups powdered sugar
3 Tbs cocoa powder
1 tsp vanilla extract
2 Tbs milk

DIRECTIONS:
Mix together all ingredients. May need to add more milk (slowly) until frosting reaches a spreadable consistency.

NOTE: When I made this, I also added 2 squares of melted unsweetened chocolate to enhance the chocolate flavor and decrease the sweetness.

CREDIT: Submitted by "Nancy Dorman" on Allrecipes.com


RAINBOW CAKE METHOD:
We can't take credit for the rainbow cake idea. Hubby is a member of the Something Awful Forums and got the idea from this thread. The vertical stripes look difficult, but are rather easy, if you follow the proportions outlined below.

How Do I Know How Much Batter To Dye Each Color?
This cake took all night and I enlisted Hubby's help. We began by calculating - yes, calculating - exactly how much of each color batter would go into each pan. We chose to use 5 colors - red, orange, yellow, green, and blue. In order for the bands of color to be about equal proportional, we actually had to use more of the blue (the outer band) than the red (the inner band).

Here are the percentages that we used of each color, with red being the inside band and blue the outside band:
Red - 10%
Orange - 15%
Yellow - 20%
Green - 25%
Blue - 30%

I'll go ahead and include our "master table" that we used to know how much of each color to use in each pan. Note that this probably won't make sense, but hopefully it will help!

The easiest way is to determine the total batter capacity of the pan and multiply the total capacity by the percentage of cake batter based on color.

Example: An 8" round pan holds 3 cups of batter. 3 cups x 10% red = 0.3 cups or approximately 1/3 cup red batter. 3 cups x 15% orange = 0.45 cups or approximately 1/2 cup orange batter.

Ok, So How Do I Get Those Cool Vertical Stripes?
Ok, now that we know how much of the batter to dye each color, let's go on to the method. Once you have all of your colored batter separated and your pans prepared, pour your first color directly into the center of the pan (your first color is the one towards the outside of the cake and the one that has the most batter from your calculations). Continue to pour the rest of the colors directly into the center of the pan until you have poured all of the batter in. Now, very carefully transfer to the oven and bake - it's that easy! Or, at least, I can say that it was easy since Hubby did that part!