Funfetti Sheet Cake
This is the cake I make when someone needs a birthday cake by tomorrow and there's no time for layers, dowels, or crumb coats. It's a single sheet pan, one bowl of frosting, and a generous handful of sprinkles folded in at the very end so they stay whole instead of bleeding color through the batter.
It reads as festive without any actual decorating skill required — the sprinkles do the visual work, and the vanilla-forward frosting keeps it tasting like a proper birthday cake instead of a plain vanilla sheet cake with sprinkles thrown on top.
Table of Contents
Why This Recipe Works
Alternating dry ingredients and milk into the creamed butter mixture keeps the batter from curdling or overmixing, which is what gives this cake a fine, even crumb instead of dense pockets. Folding the sprinkles in last, by hand, keeps their color from bleeding into the batter — stirring them in too early or too vigorously is the most common way funfetti cakes end up looking muddy instead of speckled.
Ingredients
For the cake:
- 2¾ cups (345g) all-purpose flour
- 2½ teaspoons baking powder
- ½ teaspoon salt
- 1 cup (226g) unsalted butter, softened
- 1¾ cups (350g) granulated sugar
- 4 large eggs
- 1 tablespoon vanilla extract
- 1 cup whole milk
- ¾ cup rainbow sprinkles (jimmies, not nonpareils)
For the frosting:
- 1 cup (226g) unsalted butter, softened
- 4 cups (480g) powdered sugar
- 2 tablespoons whole milk
- 1 teaspoon vanilla extract
- ¼ cup extra sprinkles, for topping
📋 Recipe Card
Funfetti Sheet Cake
- 2¾ cups (345g) flour
- 1 cup (226g) butter, softened
- 1¾ cups (350g) sugar
- 4 large eggs
- 1 cup whole milk
- ¾ cup sprinkles
- 4 cups (480g) powdered sugar, for frosting
- Whisk flour, baking powder, and salt.
- Beat butter and sugar until fluffy, then beat in eggs and vanilla.
- Alternate adding dry ingredients and milk. Fold in sprinkles.
- Spread into a greased 9x13-inch pan. Bake at 350°F (175°C) for 25-28 minutes.
- Beat butter, powdered sugar, milk, and vanilla for frosting until smooth.
- Frost the cooled cake and top with extra sprinkles.
Step-by-Step
Step 1: Mix the Dry Ingredients
Whisk the flour, baking powder, and salt together in a bowl and set aside.
Step 2: Cream the Butter and Sugar
Beat the butter and sugar together until light and fluffy, about 3 minutes. Beat in the eggs one at a time, then the vanilla.
Step 3: Combine and Add Sprinkles
Add the dry ingredients in three additions, alternating with the milk in two additions, beginning and ending with the dry ingredients. Mix just until combined after each addition. Gently fold in the sprinkles by hand with a spatula.
Step 4: Bake
Spread the batter evenly into a greased 9x13-inch pan. Bake at 350°F (175°C) for 25 to 28 minutes, until a toothpick inserted in the center comes out clean.
Step 5: Make the Frosting
Beat the softened butter until smooth and fluffy. Gradually beat in the powdered sugar, milk, and vanilla until light and spreadable.
Step 6: Frost and Decorate
Make sure the cake is fully cool before frosting, or the frosting will melt and slide. Spread evenly over the top and finish with a generous scatter of extra sprinkles before slicing.
Pro Tips
- Cool the cake completely: frosting a warm cake causes it to melt and slide right off.
- Don't overmix once sprinkles go in: a few folds is enough — more mixing means more color bleed.
- Room-temperature butter matters: cold butter won't cream properly, and the cake will end up dense.
- Add sprinkles to the frosting too: a few folded into the frosting itself adds extra texture and color.
Storage & Make-Ahead
Store frosted cake covered at room temperature for up to 2 days, or refrigerated for up to 5 days (bring to room temperature before serving for the best texture). The unfrosted cake can be baked up to 2 days ahead and stored covered, or frozen (unfrosted) for up to 3 months — thaw completely before frosting.
Variations & Substitutions
- Chocolate frosting: swap the vanilla frosting for a chocolate buttercream if you want a flavor contrast.
- Layer cake version: divide the batter between two 9-inch round pans, baking 22-25 minutes.
- Cupcakes: this batter makes about 30 standard cupcakes, baked 16-18 minutes.
- Almond extract swap: replace half the vanilla with almond extract for a bakery-style flavor twist.
FAQ
Final Thoughts
This is the recipe I keep bookmarked for whenever a birthday sneaks up on me. It looks celebratory without any real decorating effort, and it holds up well enough to make the day before if things get busy.