Funfetti cake is a vanilla layer cake with rainbow sprinkles folded into the batter, which gives every slice a colorful, speckled crumb. This from-scratch version uses standard pantry ingredients and takes about an hour start to finish. The real reason to make it instead of reaching for a box mix: the flavor is noticeably better, and it’s not much harder.
What makes this version work
Two things matter most here. First, creaming the butter and sugar long enough — a full 4 to 5 minutes — builds the air that keeps the crumb tender. A hand mixer works perfectly well; you’re just looking for the mixture to turn pale and noticeably fluffy. Second, sprinkle choice is not trivial. Jimmies (the soft, rod-shaped sprinkles) hold their color in the oven. Nonpareils — the tiny round beads — bleed almost immediately and will turn your batter gray. Stick with jimmies and fold them in last with a spatula, using only enough strokes to distribute them. Overmixing at this stage is the one thing that causes streaking.
Shopping notes
- Sprinkles: Look for jimmies specifically — the label often just says “rainbow sprinkles.” Craft stores and bulk bins usually carry better-quality jimmies than the small grocery-store bottles, and the colors stay brighter after baking.
- Whole milk: Don’t substitute skim or 2% here. The fat in whole milk contributes to the tender texture. If you only have 2%, add a tablespoon of melted butter to the cup to compensate.
- Heavy cream in the frosting: This is what makes the buttercream spreadable without being greasy. Whole milk works as a substitute but the frosting will be slightly less stable in a warm room.
Keeping it fresh
The frosted cake keeps well at room temperature, covered, for up to 2 days — the buttercream acts as a seal and the layers stay moist. Refrigerate after that, loosely covered, for up to 5 days total; bring slices to room temperature for 20 minutes before serving or the crumb will feel dense. Both the unfrosted cake layers and the buttercream freeze well separately. Wrap cooled layers tightly in plastic wrap, then foil, and freeze for up to 2 months. The frosting freezes in an airtight container for the same period — thaw it overnight in the fridge, then beat it briefly to restore the texture before spreading.
What can go wrong
- Domed, cracked tops: This usually means the oven runs hot. If your layers dome sharply, reduce the temperature by 25°F on your next bake. Domed layers are harder to stack evenly, so you can also level them with a serrated knife once fully cooled.
- Gummy or sunken center: The batter was likely underbaked. Oven thermometers are cheap and worth owning — many home ovens read 25°F lower than the actual temperature. Trust the toothpick test over the timer.
- Frosting too soft to spread cleanly: If your kitchen is warm or the butter was too soft going in, the buttercream will slide around. Chill the bowl in the fridge for 10 to 15 minutes, then beat again briefly. Skip the extra sprinkle garnish on top of the frosting if the buttercream is already struggling — not worth the extra dish when the interior sprinkles are the whole point anyway.
- Layers sliding during assembly: The cakes weren’t fully cooled. Even slight warmth softens buttercream on contact. Give the layers a full hour on the wire rack, or 20 minutes in the fridge if you’re short on time.
- Pale, flat exterior: If the cake looks underbaked on the outside but the toothpick comes out clean, that’s fine — this is a light-colored vanilla cake and it won’t brown much. What to watch for is a golden edge and a top that springs back when lightly pressed.
Funfetti Cake
Equipment
- Mixing Bowls
- Whisk
- Electric Mixer
- 9-inch round cake pans
- Offset spatula
Ingredients
For the Cake:
- 2 cups all-purpose flour preferably unbleached
- 1 tablespoon baking powder
- ½ teaspoon salt
- 1 cup unsalted butter softened to room temperature
- 1 ½ cups granulated sugar
- 4 large eggs room temperature
- 2 teaspoons pure vanilla extract
- 1 cup whole milk room temperature
- ½ cup rainbow sprinkles high quality
For the Frosting:
- 1 cup unsalted butter softened to room temperature
- 4 cups confectioners’ sugar sifted
- ¼ cup heavy cream
- 2 teaspoons pure vanilla extract
Instructions
For the Cake Base:
- Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans. Line the bottoms with parchment paper for easy removal.
- In a medium mixing bowl, whisk together the flour, baking powder, and salt. Set aside.
- In a large bowl, using an electric mixer, cream the butter and sugar together on medium speed until pale and fluffy, about 4-5 minutes.
- Add the eggs to the butter mixture one at a time, beating well after each addition. Stir in the vanilla extract.
- With the mixer on low speed, alternately add the flour mixture and milk, starting and ending with the flour. Mix until just combined.
- Gently fold in the rainbow sprinkles with a spatula, being careful not to overmix or cause the colors to run.
- Divide the batter evenly between the prepared cake pans and smooth the tops with an offset spatula.
- Bake for 25-30 minutes, or until a toothpick inserted into the center of each cake comes out clean. Allow the cakes to cool in the pans for 10 minutes, then turn out onto wire racks to cool completely.
For the Frosting:
- In a large bowl, beat the softened butter on medium speed until creamy, about 2 minutes.
- Gradually add the confectioners’ sugar, heavy cream, and vanilla extract, beating on low speed until combined, then increase to high and beat for a further 3 minutes until light and fluffy.
For the Assembly:
- Once the cakes have cooled completely, place one layer on a serving plate or cake stand. Spread a thick layer of frosting on top with an offset spatula.
- Place the second cake layer on top and spread a thin layer of frosting over the entire cake to create a crumb coat. Refrigerate for 30 minutes.
- Apply the final coat of frosting, smoothing all over with an offset spatula. Decorate with additional sprinkles as desired.
Notes
Tammy’s Tips:Â
- For added flavor, substitute half the vanilla extract with almond extract.
- To ensure the sprinkles don't bleed into the batter, use jimmies or sprinkles designed for baking.
Nutrition
Frequently asked questions
Can I make this as a single-layer sheet cake instead of two rounds?
Yes — a 9×13-inch pan works well with this batter. Bake at the same temperature and start checking at 28 minutes, since a single thicker layer can take a few minutes longer than two rounds.
Do all the ingredients really need to be at room temperature?
Yes, and it matters more than most recipes let on. Cold butter won’t cream properly, and cold eggs or milk added to creamed butter will cause it to curdle and look lumpy. If you forgot to pull things out ahead of time, set eggs in a bowl of warm water for 5 minutes and microwave the milk in 10-second bursts until it loses its chill.
Why does my frosting look greasy or separated?
The butter was likely too warm when you started beating it. Buttercream needs butter that’s soft but still cool to the touch — if you press a finger in and it sinks immediately with no resistance, it’s too warm. Chill the bowl for 10 minutes and beat again; it should come back together.
If you liked this one
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