Description

This one-pan Funfetti sheet cake is a vibrant, joyful dessert perfect for birthdays, parties, or any moment worth celebrating. With its moist vanilla base, rainbow sprinkles throughout, and fluffy buttercream frosting on top, it’s a nostalgic favorite that’s simple to make and sure to please any crowd.

Ingredients

Scale

For the cake:

2 ½ cups all-purpose flour
2 ½ tsp baking powder
½ tsp baking soda
½ tsp salt
¾ cup unsalted butter, softened
1 ¾ cups granulated sugar
4 large eggs
1 tbsp vanilla extract
1 cup buttermilk
½ cup rainbow sprinkles (jimmies style)

For the frosting:

1 cup unsalted butter, softened
4 cups powdered sugar
2–3 tbsp milk
2 tsp vanilla extract
Pinch of salt
Extra rainbow sprinkles for topping

Instructions

Preheat your oven to 350°F (175°C) and grease a 9×13-inch sheet pan.

In a medium bowl, whisk together flour, baking powder, baking soda, and salt.

In a large bowl, cream the softened butter and sugar until light and fluffy.

Add the eggs one at a time, mixing well after each, then stir in vanilla extract.

Add the dry ingredients in three additions, alternating with the buttermilk, beginning and ending with dry ingredients. Mix until just combined.

Fold in the rainbow sprinkles gently with a spatula.

Pour the batter into the prepared pan and spread evenly.

Bake for 30–35 minutes, or until a toothpick inserted into the center comes out clean. Let cool completely.

To make the frosting, beat the softened butter until smooth. Add powdered sugar gradually, followed by milk, vanilla extract, and salt. Beat until light and fluffy.

Spread the frosting evenly over the cooled cake and top with extra sprinkles.

Notes

Be sure to use jimmies-style sprinkles to prevent color bleeding in the batter.
Don’t overmix once flour is added; mix just until combined.
Always let the cake cool completely before frosting.
Customize the sprinkle colors to match holidays or party themes.

Store at room temperature in an airtight container for up to 2 days or refrigerate for up to 5.