Funfetti Sheet Cake

This cake is pure happiness in baked form. We're talking buttery vanilla cake, loads of rainbow sprinkles, and a fluffy homemade frosting that makes every bite feel like a celebration. Whether it’s for a birthday, a random Tuesday, or a “just because” treat, this Funfetti Sheet Cake brings the joy every single time.

Funfetti Sheet Cake Ingredients

• All-purpose flour – A tried-and-true base for a fluffy yet sturdy crumb. No cake flour required!
• Baking powder & baking soda – A mix of both gives this cake a gorgeous lift and tender texture.
• Butter – You’ll want it softened to room temp so it creams easily with the sugar. Salted or unsalted works, just adjust the added salt if using salted.
• Granulated sugar – Classic sweetness to let the vanilla and sprinkles shine.
• Eggs – Room temp is best for even mixing and that soft, cakey texture.
• Vanilla extract – Go for pure vanilla if you can it gives that bakery-style flavor that makes funfetti so nostalgic.
• Sour cream & milk – The sour cream keeps the crumb rich and moist, while the milk helps thin the batter for a pourable consistency. Greek yogurt works too!
• Rainbow sprinkles – The long, soft sprinkles! Avoid nonpareils they tend to bleed into the batter and create a murky look.

Let's Talk Frosting

• Butter – Make sure it’s super soft so you can whip it into a dreamy cloud.
• Powdered sugar – For that fluffy, sweet, and creamy frosting we all know and love.
• Vanilla + pinch of salt – Salt balances the sweetness, and vanilla keeps it classic.
• Heavy cream or milk – A little splash makes the texture spreadable and smooth.

How to Make a Funfetti Sheet Cake

• Whisk the dry ingredients in one bowl—flour, leaveners, salt.
• Cream butter and sugar until pale and fluffy. This is what makes your cake light!
• Add eggs and vanilla, one at a time.
• Mix in sour cream and milk—don’t worry if it looks curdled.
• Add dry ingredients and stir just until combined.
• Fold in sprinkles gently with a spatula.
• Bake in a greased 9x13 pan at 350°F for 32–36 minutes.
• Cool completely before frosting!

Tips for Success

•  Use room temperature ingredients (especially eggs, butter, and sour cream) for the smoothest batter.
• Go easy on the mixing after you add the flour—overmixing = tough cake.
• If you want cupcakes, this recipe makes about 24!
• Use parchment paper in your pan for easy removal and cleaner slices.
• Let the cake cool fully before frosting so it doesn’t melt into a mess.

FAQs

Can I make this ahead of time?
Absolutely! Bake the cake a day in advance, wrap it well, and frost it the next day. You can also store the whole cake (frosted or unfrosted) in the fridge for 2–3 days.

Can I freeze this cake?
Yes! Let the cake cool completely, then wrap slices in plastic wrap and store in a freezer bag. Freeze for up to 2 months. Thaw at room temp when ready to serve.

What kind of sprinkles should I use?
Use sprinkles, the long, soft ones. Avoid nonpareils, which tend to bleed and discolor the batter.

Can I use Greek yogurt instead of sour cream?
Totally. Full-fat Greek yogurt works great and keeps the cake nice and moist.

If you make these Funfetti Sheet Cake, I would really appreciate a comment and rating down below, under the recipe card. Don’t forget to take a picture and tag me over on Instagram, Tik Tok, or Pinterest. For more ideas, check out my Dessert Recipes page.