How to make a six-layer rainbow cake

Nothing will make you smile quite like this six-layer rainbow cake. The secret to this cake's vibrant color is to use gel food coloring-it really makes each layer pop. For an easy decorating technique, we love the "naked cake" look, which involves gently scraping frosting off of the cake for a rustic, hassle-free result. However you decorate this cake, though, it's sure to turn some heads. Naked Six-Layer Rainbow Cake Total Prep and Baking Time: 2 hours 30 minutes Serves: 15-20 For the Cake: 5 c...