Description
Funfetti Birthday Sheet Cake is a classic celebration dessert made from a light and airy vanilla cake loaded with colorful rainbow sprinkles. The term “Funfetti” refers to the sprinkles mixed into the batter, creating a festive, confetti-like appearance once baked. This cake is frosted with a smooth, fluffy vanilla buttercream that complements the sweetness of the cake perfectly. With a tender crumb and rich flavor, it’s a perfect treat for any occasion.
Ingredients
Funfetti Cake
2 ½ cups (310g) all-purpose flour
2 tsp baking powder
½ tsp baking soda
½ tsp salt
1 cup (226g) unsalted butter, softened
1 ¾ cups (350g) granulated sugar
4 large eggs, room temp
1 tbsp vanilla extract (or 2 tsp vanilla + 1 tsp almond extract for “bakery” flavor)
1 cup (240ml) buttermilk, room temp
½ cup (100g) rainbow jimmies sprinkles (not nonpareils—they bleed!)
Fluffy Vanilla Frosting
1 cup (226g) unsalted butter, softened
3 ½ – 4 cups (420–480g) powdered sugar, sifted
2–3 tbsp milk or heavy cream
1 tbsp vanilla extract (or 1 ½ tsp vanilla + ½ tsp almond extract)
Pinch of salt
Extra sprinkles for decorating 🎉
Instructions
1. Prep
Preheat oven to 350°F (180°C).
Grease or line a 9×13 pan with parchment.
2. Mix Dry Ingredients
Whisk flour, baking powder, baking soda, and salt. Set aside.
3. Cream Butter & Sugar
Beat butter and sugar 3–4 mins until pale and fluffy.
4. Add Eggs + Flavor
Add eggs one at a time, beating well.
Mix in vanilla (and almond extract if using).
5. Combine Wet + Dry
Add dry ingredients in 3 parts, alternating with buttermilk.
Mix just until combined — don’t overmix.
6. Fold in Sprinkles
Gently fold in rainbow jimmies with a spatula.
7. Bake
Spread batter evenly in the pan.
Bake 28–34 minutes, until a toothpick comes out clean.
Cool completely before frosting.
8. Make Frosting
Beat butter until smooth.
Add powdered sugar gradually.
Add vanilla, salt, and enough milk/cream for fluffy spreadable texture.
Beat 2–3 mins until light and whipped.
9. Frost & Decorate
Spread frosting generously over cooled cake.
Add lots of sprinkles on top — it’s a party! 🎊
Notes
For a festive touch, top your Funfetti Birthday Sheet Cake with colorful sprinkles, a drizzle of chocolate or vanilla glaze, or piped buttercream decorations. You can also add fresh berries or edible glitter to make it extra celebratory!
- Prep Time: 20 mins
- Cook Time: 30 mins
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 slice
- Calories: 340
Keywords: Funfetti cake, birthday sheet cake, vanilla Funfetti cake, rainbow sprinkle cake