I found a recipe for Rainbow cake on Whisk Kid. I thought that it was so cute. Then I saw Whisk Kid make it on the Martha Stewart show. When I saw it, I did think that the rainbow was cute, but all I saw was a cake for Memorial Day and the 4th of July. Red, white and blue. You see, 4th of July is my second favorite holiday. Thanksgiving is my all time favorite. We lived in Canada for a few years and while I loved living in another country, I really, really, missed my own country. The first year that we got back you would have thought that 4th of July threw up all over my house. Anything that I could put a flag, a twinkle light, red, white, or blue on, I did. I was so happy to celebrate my country. So I made this for a pre-Memorial Day party last weekend. Do you ever see a recipe and it looks beautiful on the page, but then you make it and it looks nothing like the picture? Yeah? Well, this was not one of those times. Look how pretty it is!! This cake was a huge hit with the kids and adult alike.
This cake does entail a lot of bowls. And a LOT of butter in the frosting. But it pretty simple to make. Nothing makes me feel more domestic than baking a cake. This cake in particular gave me joy. It is bright and cheerful and fun. So fun. I got giddy when I watched it being cut. So make this for your next holiday party and I promise, you will impress your friends.
3 cups flour
4 teaspoons baking powder
1/2 teaspoon salt
2 sticks unsalted butter, room temperature
2 1/3 cups sugar
5 large egg whites, room temperature
2 teaspoons vanilla
1 1/2 cups milk, room temperature
red gel food coloring
navy blue gel food coloring
Divide the batter among 3 bowls. Add red gel food coloring to one and the blue to the other. Add enough gel until it is the color that you want. Add the batter to a 9-inch (I used an 8-inch) pan that has been greased and lined with parchment. I used Baker’s Joy and they all came out like a dream. I did use a food scale to divide the batter evenly between my two pans. I had to do three bakes because I only have 2 8-inch cake pans. Spread the batter evenly as you can. These cakes are going to be thin, they bake for about 15-18 minutes in a preheated 350 degree oven.
9 large egg whites
1 3/4 cups sugar
4 sticks room temperature butter cut into small pieces
2 teaspoons lemon extract
This is a serious frosting. You need a lot to fill the layers, and to make the crumb coat and then frost the whole thing. I made it in two batches. I know the limits of the bowl of my Kitchenaid and it probably could have handled it, but the mess may have been out of control. On the stove, dissolve the egg whites into the sugar. Cook it until the sugar is melted and eggs have no more pull. It will also be hot to the touch. Put this mixture in the bowl of the mixer and using the whisk, whisk it until it comes to room temperature. Add the butter slowly one at time letting it mix for a second before you add the next one. After all the butter is added, switch to the paddle and let it beat together for 5 more minutes. It will start to break and it will come back together. Add the lemon extract.
Using about a cup of frosting for each layer, spread the frosting until it hangs over the edge. Add the next layer of cake until you stack all 6 layers. Put a very thin layer of frosting on the sides and on top of the cake. Refrigerate until the frosting is set. Take the cake out of the fridge and finish icing.
This cake serves a ton of people. It needs to be sliced thinly because it is really rich and buttery. I will also say that this cake travels really well. We took it on a long car ride. I packed it in a cake box and a cooler full of ice. It made it just fine.