Rainbow cake

I made a rainbow cake for my daughters birthday last yeat and thought I would share the recipe I got from a blog called 'all betz off'.  Its a fun cake to make and especially for a childrens

A little messy when I cut it but yum!

Rainbow layer Cake:
3 cups cake flour
4 teaspoons baking powder
1/2 teaspoon salt
2-1/3 cup sugar
1 cup unsalted butter, room temperature
5 egg whites, room temperature
2 teaspoons vanilla
1-1/2 cups milk, warmed about 30 seconds in microwave to bring to room temperature
food coloring (gels work the best)

Preheat oven to 170. Oil and line three 9" cake pans or however many you have. (I just reused the three I had.)

*Sift together the flour, baking powder, and salt. Set aside.
*Cream the sugar and butter. Add the egg whites one at a time; add the vanilla and mix until fully incorporated. Then, alternating between wet and dry, add the milk and flour mixture in two parts.
*Divide the batter between 6 bowls. (Easiest way is to do it by weight.) Stir in a fair amount of the appropriate food color to each bowl. Pour into pans and smooth out so batter is even. Bake for about 15 minutes each. 
*Remove from oven; let rest in pan on cooling rack for 10 minutes. Then flip, cover, and put them in the fridge to cool quickly.