Big Batch Confetti Cake With Buttercream

The kitchen counter looked like a rainbow explosion after my daughter decided she wanted to help me bake birthday cakes for her class. I learned that day that sprinkles have a magical way of making everything feel like a celebration, even the mess.

My nephew once told me this cake tastes like happiness in your mouth, which I think is the highest compliment a six year old could possibly give. Now every family birthday request starts with the confetti cake question.

Ingredients

• 4 cups all-purpose flour: The foundation that gives this cake structure while still staying tender and light
• 2 ½ cups granulated sugar: Creates that perfect sweetness level without becoming cloying
• 1 tablespoon baking powder: Ensures the cake rises beautifully and maintains its fluffy texture
• 1 teaspoon baking soda: Works with the baking powder for even lift and golden color
• 1 teaspoon fine sea salt: Balances sweetness and brings out all the vanilla notes
• 2 cups whole milk: Room temperature milk incorporates better and creates a tender crumb
• 1 cup vegetable oil: The secret to keeping this cake moist for days
• 1 cup unsalted butter melted: Adds that irresistible buttery flavor we all crave
• 6 large eggs: Room temperature eggs emulsify beautifully for consistent texture
• 1 tablespoon pure vanilla extract: Do not skimp here because real vanilla makes all the difference
• 1 cup rainbow sprinkles: Use jimmies specifically because they hold their shape during baking
• 2 cups unsalted butter: Room temperature butter is non negotiable for smooth buttercream
• 8 cups powdered sugar sifted: Sifting prevents lumps and ensures silky frosting
• ½ cup whole milk: Adjusts frosting consistency to spreadable perfection
• 2 tablespoons pure vanilla extract: High quality vanilla shines in simple frostings
• Pinch of salt: Cuts the sweetness and makes flavors pop
• ½ cup rainbow sprinkles: Final festive touch that makes everyone smile

Instructions

Prep your pans and oven:

Set your oven to 350°F and line two 9x13 inch pans with parchment paper for easy release later.

Whisk the dry team:

Combine flour, sugar, baking powder, baking soda, and salt in a large bowl until everything is evenly distributed.

Mix the wet ingredients:

Whisk together milk, oil, melted butter, eggs, and vanilla until the mixture looks smooth and glossy.

Bring it together:

Pour the wet mixture into the dry ingredients and fold gently until you no longer see dry streaks.

Add the magic:

Fold in the sprinkles by hand so they stay suspended throughout the batter instead of sinking to the bottom.

Bake to golden perfection:

Divide batter between your prepared pans and bake for 30 to 35 minutes until a toothpick comes out clean.

Cool completely:

Let the cakes rest in their pans for 10 minutes before moving them to wire racks to cool fully.

Make the frosting:

Beat butter until creamy then gradually add powdered sugar before whipping in milk and vanilla until fluffy.

Frost and celebrate:

Spread thick buttercream over cooled cakes and shower with extra sprinkles for that festive finish.

Save

Last summer I made this for my friend who was turning thirty and had never had a confetti cake before. Watching her face light up when she cut into it and saw all those colorful speckles reminded me why simple joys matter so much.

Making It Ahead

The cake layers can be wrapped well and frozen for up to two months before frosting. I actually think the texture improves slightly after a day in the refrigerator because the flavors have time to meld together beautifully.

Sprinkle Science

Not all sprinkles are created equal when heat is involved. I have learned through trial and error that the standard jimmies hold their shape and color while fancy quins or nonpareils will turn your cake batter into a strange grayish purple situation that no one wants to eat.

Serving Suggestions

Cut into manageable squares because this cake is rich and satisfying. A little goes a long way and you want everyone to have room for seconds.

• Chill the frosted cake for 30 minutes before slicing for cleaner edges
• Use a hot knife dipped in hot water for perfectly smooth frosting cuts
• Store covered at room temperature for up to three days

Save

There is something about slicing into a confetti cake that makes ordinary Tuesday dinners feel like special occasions. Keep this recipe handy for those moments when you need a little extra joy on the table.

Recipe FAQs

→ What type of sprinkles should I use in the cake batter?

Use jimmies (the long, thin sprinkles) in the cake batter to prevent color bleeding. Avoid nonpareils (the tiny round balls) inside the batter as they can bleed and create gray streaks. Save nonpareils for decorating the top.

→ Can I make this as a layer cake instead of sheet cake?

Yes, divide the batter between three 9-inch round pans and reduce the baking time to 25-30 minutes. The frosting quantity should still be sufficient for filling and decorating a three-layer round cake.

→ How should I store the finished cake?

Store covered at room temperature for up to 3 days. The buttercream creates a protective seal that keeps the cake moist. For longer storage, refrigerate for up to a week, though bring to room temperature before serving for best texture.

→ Can I make the batter ahead of time?

The batter should be baked immediately after mixing since the baking powder starts working once wet ingredients are added. However, you can bake the layers a day ahead, wrap tightly, and frost when ready to serve.

→ Why does this use both oil and melted butter?

The combination provides the best of both worlds: butter adds rich flavor while oil keeps the cake exceptionally moist and tender. This dual approach ensures a soft texture that lasts longer than butter-only cakes.

→ Can I freeze this cake?

Yes, wrap unfrosted cake layers tightly in plastic wrap and freeze for up to 3 months. Thaw overnight at room temperature before frosting. Already frosted cake can also be frozen, though the texture may be slightly affected.