Big Batch Confetti Cake With Buttercream

The first time I made confetti cake for my niece's birthday, she stood on a chair watching the mixer spin, absolutely mesmerized by how the rainbow specks disappeared into the pale vanilla batter. When those cakes came out of the oven, she kept peeking through the oven door asking if the sprinkles would magically come back. Seeing her face light up when I cut that first slice and revealed all those colorful flecks dotted through the tender crumb, I understood why this cake makes everyone feel like a kid again.

Last summer I made this cake for a block party and watched a grown man literally gasp when he saw the sprinkles inside his slice. Someone asked for the recipe three times before dessert was even over and two people have since texted me photos of their own confetti cake attempts.

Ingredients

• All-purpose flour: Provides the structure that keeps this towering cake from collapsing under all that festive weight
• Granulated sugar: Sweetens tenderly while creating that gorgeous golden crumb
• Baking powder and baking soda: The dynamic duo that makes this cake rise into something fluffy and light
• Fine sea salt: Balances sweetness and actually enhances vanilla flavor
• Whole milk: Adds richness and helps create that tender moist texture everyone wants in a celebration cake
• Vegetable oil: Keeps the cake incredibly moist for days which is honestly kind of dangerous
• Unsalted butter: Melted into the batter for flavor and creamed into the frosting for pure indulgence
• Large eggs: Bind everything together while adding structure and richness
• Pure vanilla extract: The backbone that lets those sprinkles shine without competing flavors
• Rainbow sprinkles: Use jimmies specifically because nonpareils will bleed into your batter and create a strange tie-dye situation
• Powdered sugar: Sifted to prevent lumps in that dreamy buttercream frosting

Instructions

Preheat your oven to 350°F and prepare two 9x13-inch pans:

The parchment paper liner is not optional unless you enjoy carving cakes out of pans with a butter knife.

Whisk together all the dry ingredients in a large bowl:

Take your time here because nobody wants to bite into a pocket of bitter baking powder.

Combine milk oil melted butter eggs and vanilla in another bowl:

Whisk until completely smooth because little pockets of melted butter will create weird streaks in your finished cake.

Pour wet ingredients into dry and mix until just combined:

Stop mixing as soon as you no longer see dry flour because overmixing makes tough sad cake.

Gently fold in the sprinkles:

Use a spatula and a light hand because you want them distributed evenly without crushing them into dust.

Divide batter between prepared pans and smooth the tops:

Drop the pans on the counter once to release any trapped air bubbles.

Bake for 30-35 minutes until a toothpick comes out clean:

Start checking at 28 minutes because nobody wants dry birthday cake.

Let cakes cool in pans for exactly 10 minutes:

Transfer to wire racks immediately after because residual heat will continue cooking the cake.

Beat room temperature butter until creamy about 2 minutes:

Scrape down the bowl because butter stuck to the sides cannot become fluffy frosting.

Gradually add sifted powdered sugar beating well after each addition:

Add milk vanilla and salt then beat on high for 3 full minutes until it looks like edible clouds.

Frost completely cooled cakes generously with buttercream:

Pile on those extra sprinkles because moderation has no place at a birthday celebration.

Save

My sister called me at midnight once because she had frosted a slightly warm confetti cake and watched in horror as all the sprinkles slid right off the sides. Now she texts me temperature updates when she bakes which I find hilarious and endearing.

Making This Ahead

The cake layers freeze beautifully wrapped tightly in plastic wrap and foil for up to a month. Just thaw them overnight on the counter before frosting day arrives.

Sprinkle Science

Jimmies are specifically designed to hold their color in batter which is why they are the only sprinkles that should go inside the cake itself. The tiny round nonpareils will bleed into your batter creating muddy streaks instead of cheerful confetti.

Serving And Storing

This cake stays moist at room temperature for up to three days covered with a cake dome or foil. For longer storage refrigerate but bring slices to room temperature before serving because cold buttercream has an unpleasant waxy texture.

• Cut small squares because this cake is incredibly rich
• Pair with cold milk or coffee to balance all that sweetness
• Store any leftovers in an airtight container to maintain freshness

Save

Every time I serve this cake someone inevitably asks what makes it so moist and I just smile because the real secret is simply not overbaking it. Happy baking and may your celebrations always be full of sprinkles.

Your Recipe Questions Answered

→ Why use jimmies instead of nonpareils in the batter?

Jimmies hold their shape during baking and won't bleed color into your cake batter. Nonpareils dissolve and create unsightly streaks, so save them for decorating the top of your frosted cake instead.

→ Can I make this cake in advance?

Yes! Wrap the cooled, unfrosted cake layers tightly in plastic wrap and freeze for up to 3 months. Thaw overnight in the refrigerator before frosting. You can also frost the cake and refrigerate it for up to 2 days before serving.

→ How should I store leftover cake?

Store covered at room temperature for up to 3 days, or refrigerate for up to 5 days. The buttercream contains butter, so it will firm up when chilled. Bring to room temperature before serving for the best texture and flavor.

→ Can I halve this recipe for a smaller batch?

This formulation works best as written since it uses whole eggs and specific ratios. For a smaller batch, bake the full amount and freeze one layer, or make cupcakes using the same batter—this yields about 48 standard cupcakes.

→ What's the best way to prevent my cake from sinking in the middle?

Avoid overmixing the batter once you add the flour, and don't open the oven door during baking. Make sure your oven is properly calibrated with an oven thermometer, and check for doneness only after the minimum bake time.

→ Can I substitute the vegetable oil?

You can use melted coconut oil or canola oil, but avoid olive oil as it has a strong flavor. The combination of oil and melted butter creates a tender crumb while maintaining the vanilla flavor profile.