Guys. Kids' birthdays are the best. It's the best reason to make a cake, because cakes for kids are whimsical, colorful, and so much fun to make. And there is no better baking "audience" than a small child. They give honest reviews, and they only care about the taste of the sugary confection; they don't care if it sits perfectly straight on the plate, or the pink wasn't the exact shade you were hoping for, or if it sinks a little in the middle.
I made this cake last year for the 2nd birthday party for a good friend's daughter. She loves M&M's (understatement), so this cake was a no-brainer. We even involved the sweet little princess in the design process. We browsed Pinterest (she's a natural), and she zeroed in on the candy-covered cakes every time, so her mom and I decided to go with a small, tiered, colorful, candy-covered, rainbow cake. Colors on colors on colors.
This cake was such a delight to make, and the colored layers were surprisingly easy. Rainbow layers are a fun, simple way to dress up a cake for any occasion. And who says rainbow layers are only for 2-year-olds? Make one for an 80th birthday! Or a Wednesday! I'm sure this cake would be a hit at any time with any age.
To make this cake, start with any white cake batter that you like. Divide the batter into separate bowls (all you need is a bowl for each color). Add a few drops of color to each bowl. I chose to do a full rainbow, so I had 7 different colors. Start with a few drops, and add more as you mix until you reach the desired color (well, a little lighter; once baked, the color will be a teensy bit darker).
This color will darken a little with baking.
Bake the layers, and then assemble as you would normally assemble a layered, tiered cake. You might notice that I did not separate these tiers. The reasons for this are twofold. One: I wanted to be able to cut through the whole thing at once for the rainbow effect, and two: this cake was small enough and light enough that it didn't really need the extra support. It might have if it was going to sit out for a long time, but it was assembled and consumed within a few hours, so everything was hunky-dory.
You could just leave it frosted for a simpler cake, or decorate any way you desire. For this cake, I completely covered the cake in stripes of M&Ms (which was so much fun!).
Needless to say, our darling birthday girl was delighted with her candy cake (her dentist probably not so much). She couldn't keep her little fingers out of the frosting, but it was her birthday, so we just let her have at it. As she should. The birthday girl gets what the birthday girl wants.
Happy birthday (last year and this year) to the most darling 3 year old I know!