I made this cake for our Independence Day BBQ. I saw it on Pinterest, decided it was worth a shot, and got going! It wasn't nearly as hard as I thought it would be, and the oohs and ahhs when I sliced it open were well worth it. This post is all about technique and not about the recipe at all.
You will need to make three layers--one white, one dyed red, and one dyed blue. I made one batch of white cake and dyed half of it blue, and made one recipe of red velvet cake (I turned the extra into cupcakes and froze them).
So, make your cake, bake it, and let the layers cool completely. I started the cake right after I got home on the third, and let it cool until right before I went to bed. I put the layers in the fridge overnight, which made all the cutting easier, I think.
So. If your layers have domed on top, slice them off so they're flat. You'll end up with some yummy leftover cake bits that you can eat later. Delish! Then, slice the white layer and the red layer in half horizontally. Do your best to make it as even and flat as possible, but don't worry if you mess it up a bit. I completely lopsided my white layers, and it didn't matter at all. Set aside one red layer and one white layer, and stack the other two.
Find yourself something circular to use as a guide for cutting the blue layer and the top red and white layers. I used the lid from an old cottage cheese container--I pressed it into the top of the cake and it left a perfect indentation that was super easy to follow when I was cutting. Try to eyeball it so that your outer layer of blue (the star field) is proportionate when you get the cake assembled. Use the same circle to cut through the red and white layer that you'll use for the top.
Now is a good time to get your frosting ready (easiest recipe ever at the bottom of this post). Place one full white layer on your cake plate and speed a layer of frosting on it.
Top with the full red layer, and spread with frosting.
Plop your big blue ring on top, and then drop the small white layer in the middle. Carefully spread some frosting on top, then finish with the small red layer. Ta da! If you've done everything right, your top layers should be perfectly nestled and you've just assembled a fabulous flag cake. Finish frosting the cake (I also topped mine with some fresh raspberries--yum!) and refrigerate it until ready to serve. Prepare yourself to be lavished with praise for your baking prowess.
Easiest ever cream cheese frosting:
Eight ounces room temp cream cheese
Two cups heavy cream
Half a cup of regular white sugar
One teaspoon vanilla
Whip the cream cheese, sugar, and vanilla in your mixer until light and fluffy. Slowly beat in the heavy cream until incorporated and holding a stiff peak. Taste, and die of happiness. Makes almost exactly enough for this cake!