Introduction

This fun and colorful funfetti cake is perfect for celebrations or any time you want a sweet treat that brings a smile. Moist, tender, and filled with rainbow sprinkles, it’s a classic crowd-pleaser with a creamy buttercream frosting to match.

A round cake with two visible layers is covered fully with smooth white frosting. The top of the cake is decorated with colorful round and rod-shaped sprinkles, which are also sprinkled evenly on the sides. The cake sits on a white plate placed on a wooden cake stand with a white marbled background. The texture of the frosting looks soft and creamy, with some light swirls on top. photo taken with an iphone --ar 4:5 --v 7

Ingredients

1 cup (220g) unsalted butter, room temperature
2 cups (400g) granulated sugar
1/2 cup (110ml) vegetable or canola oil
4 large eggs, room temperature
1 tablespoon vanilla extract
3 1/4 cups (435g) all-purpose flour
2 1/2 teaspoons baking powder
1/2 teaspoon baking soda
1 teaspoon salt
1/2 cup (125g) full-fat sour cream, room temperature
1 cup (225ml) buttermilk, room temperature
3/4 cup (140g) rainbow jimmies sprinkles
1 1/2 cups (330g) unsalted butter, room temperature (for buttercream)
5 cups (600g) powdered sugar
1 tablespoon vanilla extract (for buttercream)
2-3 tablespoons milk
1/2 cup (90g) sprinkles for decorating

Instructions

Step 1: Preheat your oven to 350°F (175°C). Grease and line the bottoms of three 9-inch cake pans with parchment paper. You can also use 8-inch pans but leave out about 1 cup of batter to avoid sinking. Fill the pans a little over halfway and optionally wrap the pans with cake strips.
Step 2: In a bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
Step 3: Using a hand or stand mixer with the whisk attachment, cream together the butter and sugar on medium-high speed for 3 to 5 minutes until light and fluffy.
Step 4: With the mixer running on low, slowly add the oil. Scrape down the bowl, then mix again briefly.
Step 5: Add the eggs one at a time, mixing well after each addition. Follow with the vanilla extract. Scrape down the bowl after every two eggs.
Step 6: Mix in the sour cream until combined.
Step 7: Add the dry ingredients and buttermilk alternately to the batter, beginning and ending with the dry ingredients (dry, wet, dry, wet, dry). Mix until just combined.
Step 8: Remove the bowl from the mixer and use a rubber spatula to scrape the bottom and sides thoroughly. Fold in the rainbow sprinkles gently to avoid color bleeding.
Step 9: Divide the batter evenly among the prepared pans and smooth the tops. Bake 30-35 minutes for 9-inch pans or 35-40 minutes for 8-inch pans. The cakes are done when a toothpick inserted in the center comes out clean.
Step 10: Let the cakes cool in the pans for 30 minutes. Run a knife around the edges, then invert onto a cooling rack and peel off the parchment. Chill the cakes in the fridge for an hour before assembling if frosting the same day.
Step 11: To make the buttercream, whip the butter until smooth using a mixer with a whisk attachment. Gradually add powdered sugar, mixing well after each cup. Add vanilla and milk as the mixture thickens, adjusting milk quantity to reach desired consistency.
Step 12: Level the chilled cakes if necessary. Spread a thin layer of buttercream between each cake layer.
Step 13: Apply a thin crumb coat around the entire cake to seal in crumbs. Chill in the fridge for 20 minutes.
Step 14: Frost the cake with the remaining buttercream, then decorate with extra sprinkles. Serve and enjoy!

Tips & Variations

Use cake strips or wet strips of cloth around pans to ensure even baking and avoid domed cakes.
Fold in sprinkles gently at the end to prevent colors from bleeding and turning the batter pastels.
If you don’t have buttermilk, make a substitute by adding 1 tablespoon of lemon juice or vinegar to 1 cup milk and let it sit for 5 minutes.
For a dairy-free version, substitute sour cream and buttermilk with plant-based yogurt or milk alternatives and use dairy-free butter for frosting.
To make cupcakes, fill liners about two-thirds full and bake at 350°F for 18-22 minutes.

Storage

Store the frosted cake covered tightly in the refrigerator for up to 4 days. For best texture, bring to room temperature before serving. Unfrosted cake layers can be wrapped tightly in plastic wrap and kept in the fridge for up to 3 days or frozen for up to 2 months. Thaw frozen cake layers overnight in the fridge before frosting.

How to Serve

A small round cake with three layers covered in smooth white frosting. The cake is decorated all over with colorful round sprinkles that create a fun and bright look. On top, the frosting is swirled in a circular pattern with more sprinkles scattered on the surface. The cake sits on a white plate, which rests on a wooden stand. The background is a white marbled texture. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use a different type of sprinkles?

Yes! Non-melting sprinkles like jimmies or sanding sugar work best to avoid color bleeding. Avoid using chocolate or edible glitter sprinkles that may melt or change texture during baking.

What if my cake sinks in the middle?

Overfilling pans or underbaking causes sinking. Fill pans only a little over halfway, and test for doneness with a toothpick before removing from the oven. Also, make sure your baking powder and baking soda are fresh.