I saw this tutorial online, and have been in love for quite some time. I decided to go the slacker way and used a box mix and 2 cans of Pillsbury icing, and made my very own Rainbow Cake!
You have to use white cake in order to get the colors to show their most vibrant.
Then Gel food coloring. I got both the Classic and Neon colors.
You divide the batter up in six bowls...you can have as many layers as you want depending on how many colors you choose to use. Then color each bowl of batter a different color.From the Classic Colors I used, red, blue, and yellow. From the Neon Colors I used, green, orange, and purple. I used about a cup of batter for each bowl, it wasn't precise and some layers were kinda thin cause I started to get low on batter.
I used 8 inch round pans, I got mine at Wal-Mart from the decorative baking section. I made sure mine had the straight edge. I used three pans.
Pour batter into pans, after having greased bottom of pan. Bake at 350 degrees for about 10 mins each. I put three in at a time. Then let cool in pan for about 10 mins.
I used squares of foil and tapped each layer out onto a sheet of foil to finish cooling. Clean pans and re-grease and pour in remaining colors into pans and bake according to previous time.
You can freeze your layers for 30 mins if you like, that way stacking and icing is easier and yields less crumbs. Place first layer on cake platter, I started with purple, then take some frosting and cover top of layer with frosting. Stack next layer, and cover with frosting, continue till all layers are stacked and have a basic amount of frosting to cover thinly. Let chill for 15 mins in fridge to make final layer of frosting go on smoothly. (I didn't chill the layers or the cake before frosting and had more crumbs and crumbly bits with the frosting.) Take remaining frosting and with frosting spatula start on top of cake smooth frosting out and working your way down the sides.
Final result was sooo fun to eat! and soo colorful and happy :0) So go make yourself a happy rainbow cake!