There’s nothing quite like the joy of a homemade birthday cake – from the moment you mix the batter to the first slice dripping with frosting. This rainbow sprinkle birthday cake is a celebration in itself: soft, buttery layers soaked in a hint of vanilla, topped with creamy, tangy frosting, and finished with crunchy, colorful crumbs that add both texture and fun.
Perfect for birthdays, special occasions, or any time you want to bring a little magic to the table, this cake is as delightful to bake as it is to eat. With a tender crumb, a moist texture, and frosting that’s rich but balanced, it’s a cake that everyone will love.
Whether you’re a seasoned baker or trying your hand at a show-stopping dessert for the first time, this recipe breaks down every step – from the batter to the frosting to the crumb topping – so you can create a cake that’s as beautiful as it is delicious.
Tools & Equipment
- 2 strips of acetate 50cm / 20-inch
- Cake ring 15 cm / 6-inch
- Curved spoon
- Large baking sheet
- Liquid measuring cup
- Medium bowl
- Parchment paper/silicone baking mat
- Quarter baking sheet
- Silicone spatula
- Stand mixer fitted with the paddle attachment
- Whisk
- Wire rack
Recipe Tips
Plan ahead: The cake and crumbs need to cool completely after baking, therefore prepare them in advance. The frosting can be used directly, that’s why I make it just before I assemble the cake.
Even Layering: When assembling, use a cake ring and acetate strips to keep layers straight and neat. Press crumbs gently into frosting to anchor them, but don’t overpress, or the layers may get squished.
Overnight Rest: Wrap and refrigerate the baked cake overnight before frosting. This makes it easier to handle and helps layers hold their shape.
Storage Matters: Keep the cake in the fridge, especially because of the cream cheese frosting. Follow freezing instructions if you want to make it ahead for celebrations.
Serving: Slice with a sharp, warm knife for clean layers. Wipe the knife between cuts for the perfect presentation.
Ingredients You Need for the Birthday Cake
For the cake, butter adds richness and moisture while helping create a tender crumb, and vegetable shorteningcontributes to a soft texture and helps the cake stay moist longer. Granulated sugar sweetens the batter and creates a light, airy structure, while light brown sugar adds extra moisture with subtle caramel notes. Eggs provide structure, stability, and richness, assisting in the cake’s rise, and buttermilk adds tangy flavor and reacts with baking powder to enhance lightness. Grapeseed oil keeps the cake tender without affecting the flavor, and vanilla extract brings aromatic depth. Cake flour ensures a fine, delicate crumb, while baking powder helps the cake rise and stay fluffy. Finally, saltbalances the sweetness, and rainbow sprinkles add playful bursts of color and texture throughout the cake.
For the crumbs, granulated sugar sweetens and creates a slight crispness, while light brown sugar adds moisture and caramel notes. Cake flour keeps the crumbs tender, and baking powder helps them hold their shape. Salt enhances the overall flavor, rainbow sprinkles add color and playful texture, grapeseed oil keeps them moist, and vanilla extract adds a fragrant, sweet note.
The frosting relies on butter for creaminess, while vegetable shortening stabilizes it to hold its shape. Cream cheese adds tang and richness, and light corn syrup creates a smooth, glossy finish. Vanilla extract elevates the flavor, while powdered sugar sweetens and thickens the frosting. A pinch of salt balances the sweetness, baking powder gives subtle lift, and citric acid adds a gentle tang to counter the richness of the butter and cream cheese.
Finally, the soak uses milk to add moisture and soften the layers, while vanilla extract brings a sweet, aromatic finish that ties all the flavors together.
Directions – How to Make Birthday Cake
Make the Cake
Preheat the oven to 180°C / 350°F. Grease a quarter sheet pan with pan spray and line it with parchment paper. In the bowl of a stand mixer fitted with the paddle attachment, cream together butter, shortening, and both sugars for 2–3 minutes on medium-high speed until light and fluffy. Scrape down the sides of the bowl. Add the eggs one at a time, beating for 1 minute after each addition on medium-high. Scrape down the sides, then mix on high for 4 minutes until fully incorporated. Scrape down the bowl again.
Combine buttermilk, oil, and vanilla. Gradually add this mixture to the batter on low speed. Increase to medium-high and beat for 2–3 minutes, until the mixture is pale, doubled in volume, and completely homogeneous. Stop the mixer and scrape down the sides of the bowl.
In a medium bowl, whisk together cake flour, baking powder, salt, and 50g of rainbow sprinkles. Add the dry ingredients to the batter on very low speed and mix for 45–60 seconds until just combined. Scrape down the sides and mix again on low for 45 seconds.
Spread the batter evenly in the prepared pan with a spatula. Sprinkle the remaining rainbow sprinkles on top. Bake on the center rack for 30–35 minutes, rotating the pan halfway through. The cake should rise and double in size. After 30 minutes, gently tap the edge of the cake; it should spring back slightly, and the center should no longer jiggle. If not, leave in the oven 3–5 minutes longer. Remove from the oven and cool completely on a wire rack. Wrap in plastic and refrigerate overnight.
Make the Crumbs
Preheat the oven to 150°C / 300°F. Line a baking sheet with parchment paper. In a stand mixer, combine sugar, cake flour, baking powder, salt, and rainbow sprinkles on low speed until evenly mixed. Add oil and vanilla, mixing just until the dry ingredients form small clumps.
Spread the clumps evenly on the prepared baking sheet and bake for 20 minutes. Cool completely before using.
Make the Frosting
In the bowl of a stand mixer fitted with the paddle attachment, beat butter, shortening, and cream cheese on medium-high for 2–3 minutes until smooth and fluffy. Scrape down the sides of the bowl. Add light corn syrup and vanilla on low speed, then increase to medium and beat for 2–3 minutes until pale and creamy.
Add powdered sugar, salt, baking powder, and citric acid on low speed to incorporate, then beat on medium-high for 2–3 minutes until smooth and glossy.
Assemble the Birthday Cake
For the vanilla soak combine milk and vanilla extract in a small liquid measuring cup. Stir until well blended. Place a piece of parchment paper on your work surface. Remove the cake from the pan and peel off the bottom parchment.
Using a cake ring, cut out 2 circles for the top layers. Gather the remaining cake scraps to form the bottom layer. Clean the cake ring and place it on a Silpat-lined sheet pan. Line the inside of the ring with 1 strip of acetate.
Arrange the cake scraps in the ring and press gently with your hand to create a flat, even layer. Spoon half of the vanilla soak over the cake layer. Spread one-fifth of the frosting evenly on top.
Sprinkle one-third of the crumbs over the frosting and press lightly to anchor. Spread another fifth of the frosting evenly over the crumbs.
Carefully insert a second acetate strip inside the cake ring, 5–6 inches high. Place the next cake round on top and repeat the process for the second layer. Place the final cake round on top and spread the remaining frosting over the top and sides.
Decorate with the remaining crumbs. Transfer the cake to the fridge and chill for at least 12 hours to allow it to set. Transfer the cake to a serving plate and remove the cake ring and acetate carefully. Slice and enjoy.
Storing and Freezing Instructions
Storing: To keep the cake fresh, store it in the refrigerator, covered loosely with plastic wrap or in an airtight container. It will maintain its moisture and flavor for up to 3–4 days. Avoid leaving the cake at room temperature for extended periods, as the cream cheese frosting may soften too much.
Freezing: You can freeze the cake for longer storage. Wrap the fully assembled cake tightly in plastic wrap and then in aluminum foil to prevent freezer burn. The cake can be frozen for up to 2–3 months. If freezing cake layers separately, wrap each layer individually in plastic and foil before freezing.
Thawing: To thaw, transfer the cake to the refrigerator and leave it covered for 6–8 hours or overnight until completely defrosted. For quicker thawing, leave the wrapped cake at room temperature for 2–3 hours, but ensure it stays in a cool, dry place to prevent the frosting from softening too much. Once thawed, the cake can be served as usual.
My Summary for Birthday Cake
Taste: This birthday cake is sweet but balanced, with layers of buttery richness from the butter and vegetable shortening. The brown sugar adds a subtle caramel note, while the cream cheese frosting provides a tangy, creamy contrast that prevents the cake from being overly sweet. The vanilla throughout the batter, soak, and frosting gives it a warm, aromatic flavor that complements the colorful rainbow sprinkles, adding a fun, festive touch without overpowering the palate.
Texture: The cake is moist and tender, thanks to the combination of butter, grapeseed oil, and buttermilk. The cake flour ensures a fine, delicate crumb, while the stand mixer’s beating steps create a light and airy structure that rises beautifully. The soak keeps each layer soft and evenly moist, preventing dryness. The frosting is smooth, creamy, and spreadable, while the rainbow sprinkles in both the cake and crumbs give subtle bursts of texture and a slight crunch. Overall, the cake is light yet rich, with a melt-in-your-mouth quality that contrasts beautifully with the crunchy, colorful crumb topping.
How Long It Takes to Make a Birthday Cake: A Step-by-Step Timeline
- Prepare ingredients & preheat oven: 10 minutes
- Make the cake batter: 15–20 minutes
- Bake the cake: 30–35 minutes
- Cool the cake: 30–40 minutes
- Wrap and chill cake overnight: 8–12 hours (inactive)
- Make the frosting: 10–15 minutes
- Make the crumbs: 15–20 minutes
- Bake crumbs: 20 minutes
- Cool crumbs: 15–20 minutes
- Prepare the soak: 2–3 minutes
- Assemble the cake: 30–40 minutes
- Chill assembled cake: 12 hours (inactive)
Total Time Estimate
- Active prep time: 2.5–3 hours
- Inactive time (chilling): 20–24 hours
- Total time: 22.5–27 hours
More Recipes to Try
- B’Day Truffles
- Biscoff Layer Cake
- Chocolate Malt Layer Cake
- Confetti Cookies
- Raspberry Mousse Cake
- Strawberry Vanilla Layer Cake
- Vanilla Birthday Cake
