Epic Rainbow Cake Recipes

Steps:

• Preheat the oven to 375 degrees F. Spray the bottom and sides of six 8-inch round cake pans; dust with flour and tap out excess.
• Whisk together the flour, baking powder and salt in a medium bowl; set aside.
• Beat the butter, sugar and oil in a large bowl with an electric mixer on medium-high speed until light in color and fluffy, about 5 minutes. Beat in the eggs, one at a time, then the vanilla seeds, until combined.
• Transfer the creamed mixture to a very large mixing bowl, then alternate folding in the flour mixture and the milk with a spatula, adding the flour in 3 additions and the milk in 2, starting and ending with the flour, just until smooth. Divide the batter equally among 6 mixing bowls. Using gel food colors, tint each bowl with one of the colors of the rainbow. Pour each color into its own prepared cake pan.
• Bake, rotating the pans halfway through, until a toothpick inserted in the centers comes out clean, 18 to 20 minutes. Cool the cakes in the pans on a rack for 10 minutes, then remove the cakes to the rack to cool completely.
• Level the tops of any cake layers that have domed by slicing the domes off with a serrated knife. Put some buttercream into a pastry bag fitted with a large round tip. Put the bottom cake layer onto a cake plate. Pipe around the edge of the cake layer to create a frosting "dam." Fill the center with a thin layer of jam (about 1/2 cup). Top with another cake layer and repeat until you have stacked and filled all the layers. Frost the outside of the cake with the remaining buttercream and decorate as desired.
• In the bowl of a stand mixer, combine the confectioners' sugar, butter, milk, vanilla seeds and salt. Beat on low speed for a while. When the sugar is incorporated, turn the speed up and beat until the buttercream is fluffy and smooth. If it's too wet, add a bit more confectioners' sugar. If it's too stiff, add a bit more butter. Be sure to scrape the sides of the bowl once or twice to make sure everything is combined.
• Use immediately or store in an airtight container at room temperature for up to 24 hours or in the fridge for up to 2 weeks. Rewhip cold buttercream before using.

Steps:

• Preheat the oven to 350 degrees F (175 degrees C). Spray two 9-inch cake pans with cooking spray.
• Combine cake mix, egg whites, water, and applesauce in a large bowl using an electric mixer. Divide batter evenly into 6 bowls. Mix a different food coloring gel into each bowl. Pour the red batter and orange batter separately into the prepared cake pans.
• Bake in the preheated oven until a toothpick inserted into the center of each cake comes out clean, 25 to 30 minutes.
• Remove from the oven and let rest on a cooling rack in the pans for 15 minutes. Flip quickly onto the rack and remove cakes from the pans. Continue the baking and cooling process with remaining batter until all layers are cooled.
• Shave off the tops of the cakes carefully using a large knife so they will be flat. Place the red layer down, frost the top lightly; continue with orange, yellow, green, blue, and purple.
• Frost the top and outside of the cake. Cut through using a big, sharp knife and serve.

Steps:

• Preheat oven to 350 degrees. Brush six 9-inch-round cake pans (or as many 9-inch cake pans as you have, reusing them as necessary) with shortening. Line bottom of each cake pan with parchment paper; brush again and set aside.
• In a large bowl, whisk together flour, baking powder and salt; set aside. In the bowl of an electric mixer fitted with the paddle attachment, cream together butter and sugar. Slowly add egg whites and mix until well combined. Add vanilla and mix until fully incorporated. Add flour mixture and milk in two alternating additions, beginning with the flour and ending with the milk. Mix until well combined.
• Divide batter evenly between six medium bowls. Add enough of each color of food coloring to each bowl, whisking, until desired shade is reached. Transfer each color to an individual cake pan. Transfer to oven and bake until a cake tester inserted into the center of each cake comes out clean, about 15 minutes (working in batches if necessary).
• Remove cakes from oven and transfer to a wire rack; let cool for 10 minutes. Invert cakes onto a wire rack; re-invert and let cool completely.
• Using a serrated knife, trim tops of cakes to make level. Place four strips of parchment paper around perimeter of a serving plate or lazy Susan. Place the purple layer on the cake plate. Spread a scant 1 cup buttercream filling over the first layer with a small offset spatula so it extends just beyond edges. Repeat process with blue, green, yellow, and orange layers.
• Place the remaining red layer on top, bottom-side up. Gently sweep away any loose crumbs with a pastry brush. Using an offset spatula, cover the top and sides with a thin layer of frosting (also use any of the excess frosting visible between the layers). Refrigerate until set, about 30 minutes.
• Using an offset spatula, cover cake again with remaining frosting.