For a unique twist on a classic sandwich, try making a peanut butter and jelly cake for your child's birthday. Start by baking two layers of vanilla cake. Once the cakes have cooled, spread a layer of peanut butter on one cake layer and a layer of jelly on the other. Sandwich the two layers together and frost the entire cake with a creamy peanut butter frosting. You can also add a drizzle of jelly on top for added flavor. This cake is a nostalgic and delicious treat that kids will love.