Rainbow Birthday Cake with Sprinkles

A beautiful, bright, show-stopping, delicious Rainbow Birthday Cake with Sprinkles. Nothing beats slicing into this cake and seeing the vibrant colors of the rainbow! This cake is perfect for birthdays and other special occasions!

This decadent and vivid Rainbow Birthday Cake is gorgeous and a crowd-pleaser!

This rainbow birthday cake with sprinkles has 6 bright, colorful layers from the rainbow: Red, orange, yellow, green, blue, and violet. The acronym ROYGBIV (red, orange, yellow, green, blue, indigo, and violet) is useful to remember the order of the rainbow colors. As indigo and violet are fairly similar, you can skip them. To decorate this rainbow birthday cake I add Fluffy Buttercream Frosting between each layer and frost the cake with vanilla buttercream. Then I add multi-colored sprinkles to the entire body of the cake and use a piping bag and star nozzle to create swirls around the rim of the cake.

If you are a fan of sprinkles, you will love this Old-School Birthday Sprinkle Cake! For more colorful and themed cakes, try my Mini Egg Easter Drip Cake, Chocolate Oreo Drip Cake with Oreo Frosting, Easy Mango Passionfruit Cake and Japanese Matcha Cake with Strawberries and Cream.

Why You Should Try This Recipe

• Every time I make this rainbow birthday cake with sprinkles I see the delight in people’s faces when they get their first slice. It brings life to the phrase “Taste the rainbow ”
• This rainbow birthday cake with sprinkles always adds excitement to special occasions!
• This is a super easy rainbow birthday cake with sprinkles recipe for a colorful, kid-friendly cake—and trust me, there will be no leftovers!
• Feel free to experiment with this bright cake’s frosting—you can try chocolate, strawberry, or any other flavor you wish. You may always use white flour or GF flour in place of self-raising flour.
• Every bite of this rainbow birthday cake with sprinkles is indulging!
• Design this rainbow birthday cake however you like. For example, frost it with vanilla buttercream or Easy Milk Chocolate Ganache.

Ingredients

This rainbow birthday cake with sprinkles recipe uses easy-to-find ingredients that can be bought from a local store if you don’t already have them in your pantry. Read the Recipe Card for the measurements.

For Rainbow Cake 

This is a 6” cake with 6 layers of vanilla sponge. This vanilla sponge is made with butter using the creaming method. All ingredients should be at room temperature and all dry ingredients should be sifted (poured through a sieve) before baking. 

• Unsalted butter: I have used unsalted butter. Any local brand works. Ensure the butter is at room temperature when you start with steps.
• Caster sugar: is finer than granulated sugar and dissolves easily with melted butter.
• Vanilla extract: I prefer using vanilla extract over essence as the extract adds a strong aroma and flavor to this rainbow birthday cake with sprinkles. 
• Eggs: Eggs add natural structure and moisture to this cake, helping create a fluffy and soft cake. Make sure they are at room temp.
• Self-raising flour: Sift the flour to remove lumps.
• Milk: I have used full-fat milk and recommend using it. To make this layer cake vegan, use vegan milk or yogurt.
• ⅛-1/4 teaspoon of red, orange, yellow, green, blue, and violet food coloring gel. Each gel is of rainbow color. 

• Unsalted butter: Use room-temperature butter to achieve the best texture.
• Icing sugar: Sift the sugar to remove lumps.
• Vanilla extract: For sweetness.
• Sprinkles: Any local good brand will work.

Equipment

• Piping bags
• 6” Cake tins
• Cake board
• Cake turntable
• Water bottle for syrup
• Cake smoother

Tips and Substitutions

• Cake tins: This rainbow birthday cake with sprinkles is tall as I used 6″ cake tins. You can also use 7″ tins or 8″ tins. However, be aware that the cake layers will be thinner.
• Different proportions: You can double or triple this rainbow birthday cake recipe depending on how many people you feed. If you want to make a smaller amount, the cake layers will be thinner, and this can sometimes be difficult to decorate.
• Ingredients: Make sure that all of the ingredients are at room temperature. Sift all of the dry ingredients before mixing.
• Overmixing batter: Do not overmix the batter because the cake will become tough.
• Baking: Cakes should be baked on the middle shelf. Baking cakes on the top shelf can result in dry burnt cakes and baking cakes on the bottom shelf can take longer. Add cakes to the oven as soon as possible for the best results. Also, do not open the oven in the first 20 minutes of baking. If you don’t have space for 6 tins in your oven then you can half the recipe below and make three cakes first and then bake the remaining three.
• Moisture: If you want to add more moisture to the cake, heat a 1:1 ratio of water and sugar in a saucepan to create a syrup. Bring to a boil, simmer for 10 minutes, and leave to cool.
• Different ways to decorate: You can decorate this rainbow birthday cake in many ways. If you want a simple look, skip the sprinkles and frost the cake with vanilla buttercream. You can also add chocolate drips or use rainbow-colored buttercream!

Recipe Variations

• Rainbow Cheesecake: If you love cheesecake, this rainbow birthday cake can be easily made as cheesecake. Make a base of graham crackers. Mix sour cream, cream cheese, cream, and eggs and divide into parts. Add color to each part and add to the top of the graham base. Bake this colorful cake!
• Easy Rainbow Unicorn Cake: Make this cake a designer cake by adding a unicorn shape for your kid!
• Eggless Rainbow Cake: If you dislike egg flavor in cakes, feel free to replace it with flax egg, yogurt, and oil.
• Rainbow Jello Cake: Twist this rainbow birthday cake recipe by adding colorful jello to the cake batter!

How to Make Rainbow Birthday Cake with Sprinkles

This rainbow birthday cake is bright, fun, and delicious! The steps below will guide you through making a rainbow birthday cake from scratch.

Prep Baking Tins

Preheat the oven to 160C/320F/Gas mark 3. If necessary, grease 6 non-stick 6″ cake tins with butter or oil and line them with baking paper.

Mix Ingredients

1. In a large bowl, add room-temperature butter and sifted caster sugar. Whisk for a few minutes or until pale yellow.

2. Mix vanilla extract into the butter-sugar mixture. To this, add an egg and mix well until the egg is not visible.

3. Keep adding the remaining eggs in a similar way. If you add all of the eggs at once the mixture may split and curdle. The mixture should look smooth and silky.

4. Gradually add sifted self-raising flour (not all at once) to the mixture and room temperature milk and mix.

5. Add the rest of the self-raising flour and milk then mix. 

Note: Do not overmix the cake batter as you still need to mix in food coloring. Overmixing will result in a tough cake.

Color Up the Layers

6. You will need red, orange, yellow, green, blue and violet food coloring. I suggest you use the gel as the colors come out a lot more vibrant. Add equal amounts of the cake batter to six different bowls and add each food coloring and mix until well combined.

Add each colored cake batter into the greased tins and bake for 30 minutes or until done. 

7. To test if your cake is ready, stick a knife into it. If it comes out clean, then it is done, but if it is wet with cake batter, then it’s not ready. Once the cakes are ready, leave them to cool completely on a cooling rack before decorating.

As you can see from the image above, not all cakes appear to be the right color. Don’t worry this is perfectly normal because most cakes get burnt on the outside. All you need to do is use a knife to shave off the burnt bits and the color will come through.

Prep Easy Vanilla Buttercream

9. Take another bowl and add room-temperature unsalted butter. Whisk on a low speed for 1 minute. Then add some sifted icing sugar and whisk on medium speed for 3 minutes.

10. Add the remaining sifted icing sugar, vanilla extract, and double cream. Whisk for 3-5 minutes or until spreadable. You can use my Best White Chocolate Buttercream or Whipped White Chocolate Ganache to frost the cake instead.

Assemble The Rainbow Birthday Cake

11. Make sure you stack the cakes in the correct order once it’s time to decorate.

12. Add buttercream to the center of an 8″ cake board. Then place the violet cake on the board. Option to add homemade syrup to the cake to keep it moist. Then add buttercream. Repeat this step for the rest of the cakes.

Syrup Recipe (optional): Heat a 1:1 ratio of water and sugar in a saucepan to create a syrup. Bring to a boil, simmer for 10 minutes and leave to cool. This helps the cake to stay moist.

13. Then add buttercream to a piping bag and cover the cake in buttercream. Use a smoother to smooth the cake. I recommend refrigerating the cake for 30 minutes.

14. You can add a second layer of buttercream or skip this and add sprinkles to the entire body of the cake using your hands or a spoon.

15. Finally, add a star nozzle to a piping bag, add buttercream and add swirls around the rim of the cake.

16. Serve the show-stopping rainbow birthday cake! Cut into the cake, take your first slice, and admire the beautiful rainbow colors! 

Recipe FAQS

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