The Double Rainbow Cake is a vibrant celebration of color and flavor that’s as delightful to make as it is to eat. With just 30 minutes from start to finish, this recipe brings a burst of joy to any occasion. Each slice reveals layers of soft, moist cake infused with bright, fruity flavors that dance on your palate. The smooth, creamy frosting adds a luscious contrast, making every bite a perfect harmony of textures.
This cake isn’t just a treat for the taste buds—it’s a feast for the eyes, too. Its dazzling hues and fluffy crumb make it a showstopper at parties or a sweet pick-me-up for everyday moments. The simplicity of the prep time means you can whip up this masterpiece without stress, leaving you more time to savor the magic. Whether you’re baking for a crowd or indulging solo, the Double Rainbow Cake promises to brighten your day with every slice.
Ingredients for Double Rainbow Cake
- Dry Ingredients:
- 3 2/3 cups (25 oz/710g) all-purpose flour (or cake flour)
- 1 tsp baking powder
- 1/2 tsp baking soda
- 1 tsp salt
- 1 1/2 cups (12 oz/340g) granulated sugar
- 1/2 cup (4 oz/115g) light brown sugar
- Wet Ingredients:
- 1 cup (8 oz/225g) butter, melted
- 2 large eggs
- 1/2 cup (4 oz/113g) plain yogurt or sour cream
- 1 1/2 cups (12 oz/340g) buttermilk (make your own by mixing milk with 3 tbsp lemon juice or white vinegar)
- 2 tbsp vanilla extract
- Food Dye: Red, yellow, orange, violet, blue, and green (use good quality, concentrated dyes)
- Vanilla Buttercream Frosting:
- 1 1/2 cups (12 oz/340g) butter, at room temperature
- 3 cups (1 lb 8 oz/680g) icing sugar, sifted
- 2 tsp vanilla extract
Step-by-Step Instructions
- Preheat the oven to 350°F (175°C). Grease and line a 9-inch springform or baking pan. (For a taller cake, use a 6-inch pan, but you’ll have leftover batter for cupcakes.)
- Mix dry ingredients: In a medium bowl, combine flour, baking powder, baking soda, both sugars, and salt. Set aside.
- Melt butter: In a microwave-safe bowl, melt the butter and set aside to cool slightly.
- Whisk wet ingredients: In a jug, whisk together eggs, yogurt, buttermilk, and vanilla extract until combined.
- Combine wet and dry ingredients: Slowly mix the wet ingredients into the dry ingredients. Toward the end, add the melted butter. Mix until just combined—do not overmix, as this will toughen the cake.
- Color the batter: Divide the batter into 6 bowls. Add a generous drop of food dye to each bowl and mix until the desired color is achieved. Avoid overmixing.
- Layer the batter: Spoon the colored batter into the prepared pan, alternating colors to create a marbled effect.
- Bake the cake: Bake for 45-55 minutes (or 1 hour 10 minutes to 1 hour 20 minutes for a 6-inch pan) until a toothpick inserted into the center comes out clean.
- Make the buttercream: Beat the butter on medium speed for 8-10 minutes until pale and fluffy. Gradually add the icing sugar on low speed, then beat for another 5 minutes. Add vanilla and mix until fluffy. Chill the frosting before use.
- Color the frosting: Divide the frosting and add food dye to match the cake colors.
- Assemble the cake: Slice the cake into layers (5 layers recommended). Spread colored frosting between the layers to continue the rainbow effect.
- Crumb coat: Spread a thin layer of frosting around the cake and refrigerate for 20 minutes to set.
- Create the ombre effect: With a small spatula, spread thin lines of colored frosting around the cake, working from dark to light (purple at the bottom to red at the top). Gently blend the colors with a spatula for a smooth finish.
- Serve and enjoy: Slice and enjoy your stunning Double Rainbow Cake!
Storage and Reheating Tips
Store your Double Rainbow Cake in an airtight container at room temperature for up to 2 days, or in the fridge for up to 5 days. If refrigerated, let it sit at room temperature for 30 minutes before serving to soften the frosting. For longer storage, wrap individual slices in plastic wrap and freeze for up to 2 months. Thaw in the fridge overnight before enjoying.
Time-Saving Hacks
To save time, prepare the cake batter and frosting the night before. Store the batter in separate bowls, tightly covered, in the fridge, and keep the frosting in an airtight container. When ready to bake, let the batter come to room temperature before coloring and baking. You can also use pre-made buttercream frosting, though homemade is highly recommended for its fluffiness.
Equipment Guidance
For best results, use a 6-inch springform pan for a taller cake, or a 9-inch pan for a wider one. A stand mixer or hand mixer is ideal for the buttercream frosting to achieve that light, fluffy texture. Don’t forget a spatula for smoothing the frosting and a toothpick to check the cake’s doneness. If you’re layering the cake, a serrated knife will help you slice it evenly.
Recipe Variations
Try using different food dye combinations for unique themes, like pastel shades for a baby shower or bold colors for a birthday. You can also swap the vanilla buttercream for cream cheese frosting for a tangy twist. For a gluten-free version, substitute the all-purpose flour with a gluten-free blend, and ensure all other ingredients are gluten-free certified.
Common Questions Answered
Can I use regular milk instead of buttermilk? Yes, mix 1 1/2 cups of milk with 3 tablespoons of lemon juice or white vinegar and let it sit for 5 minutes. What if I don’t have yogurt? Sour cream or even applesauce can be used as a substitute. How do I prevent overmixing? Stir until just combined—overmixing can make the cake dense. Happy baking!
Double Rainbow Cake
Ingredients
Dry Ingredients
- 3 2/3 Cups all-purpose flour (or cake flour) 25ozs/710g
- 1 tsp baking powder
- 1/2 tsp baking soda
- 1 tsp salt
- 1 1/2 Cup granulated sugar 12oz/340g
- 1/2 Cup light brown sugar 4oz/115g
Wet Ingredients
- 1 Cup butter, melted 8oz/225g
- 2 Large egg
- 1/2 Cup yogurt plain or sour cream 4oz/113g
- 1 1/2 Cup Buttermilk 12oz/340g (make buttermilk by mixing milk with 3 tablespoons of lemon juice or white vinegar)
- 2 Tbsp vanilla extract
Food Dye
- Food dye (Good quality and concentrated) red, yellow, orange, violet, blue and green
VANILLA BUTTERCREAM FROSTING
- 1 1/2 cups Butter, at room temperature 12oz/340g
- 3 cups Icing sugar, sifted 1lb 8oz/680g
- 2 tsp Vanilla extract
Instructions
- Preheat oven to 350F degrees. Grease and line a 9 inch springform or baking pan. I used a 6inch to get a higher cake. If you do you will have some mix left over for cupcakes.
- In a medium bowl mix together all the dry ingredients, flour, baking powder, baking soda, both sugars and salt.
- In a bowl, melt butter in the microwave and set aside.
- In a jug , whisk in the wet ingredients minus the butter- egg, yogurt, buttermilk, and vanilla extract until combined.
- Slowly mix the wet ingredients into the dry. Towards the end of mixing add in the melted butter. The batter will be thick. Do not beat or over mix as this will toughen your cake.
- To color the cake: Divide the batter into 6 bowls. Add a generous drop of food dye to each bowl. Mix until you have reached your desired color. Try to add enough at the start to avoid over mixing your cake batter.
- Now for the fun part: Spoon the batter into prepared cake pan, alternating the color. Lay the colors over each other to create a beautiful marbled effect in the end cake.
- IMPORTANT NOTE: Bake for roughly 45-55 minutes. Depending on size cake you make 1hr 10- 1hr 20 minutes or until a toothpick inserted in the center comes out clean. This is a thick cake so it will take some time.
- To make the Buttercream- On Medium speed beat the butter for about 8-10 minutes on its own. This makes a huge difference in the end so be patient and you will be rewarded with amazing frosting.
- When pale in color, add powdered sugar spoonful by spoonful on Low speed. This helps make a fluffy frosting too.
- Turn off the mix and run a spatula under and around the frosting to make sure all ingredients are incorporated. Add vanilla and salt and beat on medium speed for another 5 minutes. The frosting will almost double in size and will be so fluffy and pale in color. It helps to chill your frosting before use so its not too soft.
- Color your frosting with drops of food dye like you did with the cake batter until you reach your desired color.
- Slice your cake in layers. I did 5 layers, but you can do as many or as little as you like.
- Spread your colored frosting in the layers of the cake to continue the rainbow color. Then spread the overflowing icing around the cake to create the crumb layer. Pop in the fridge for 20 minutes and let the icing set. This will make it easier to do the final coating.
- To create an Ombre Rainbow on the outside – With a small spatula (or even a knife) spread thin line of your frosting around the bottom and work up your way up the cake going from dark to light. I did purple, blue, green, yellow, orange and red on the top. It will be rough, and there will be bumps and holes but don’t worry :).
- Once you have done a thin line of all of your colors take a spatula and run it GENTLY around the cake blending and smoothing the colors. You don’t want to take away frosting doing this, just smooth the end result. Now enjoy your amazing Double Rainbow Cake creation!
