Name: Easy Funfetti Birthday Bundt Cake Recipe
Prep time: 20 min
Cook time: 45 min
Total time: 65 min
Ingredients: 2 ½ cups all-purpose flour; 2 ½ tsp baking powder; ½ tsp fine sea salt; 1 cup unsalted butter, softened; 2 cups granulated sugar; 4 large eggs, room temperature; 1 tbsp pure vanilla extract; 1 cup buttermilk, room temperature; ½ cup rainbow sprinkles (jimmies); 1 ½ cups powdered sugar; 2 to 3 tbsp milk; ½ tsp vanilla extract; Extra sprinkles for topping

This easy funfetti birthday Bundt cake is a colorful, crowd-pleasing dessert that comes together in one bowl. Soft vanilla cake studded with rainbow sprinkles and topped with a simple glaze makes any day feel like a celebration.

No fancy decorating skills required, just a trusty Bundt pan and a handful of pantry staples. It’s the kind of cake that shows up at a party and disappears fast, no begging required.

Why This Bundt Cake Always Gets the Party Started

I love a cake where the pan does half the work. The Bundt shape adds instant height and drama, and the sprinkles hide any uneven crumb without fuss.

The texture is tender and moist, thanks to buttermilk and a generous amount of butter. A quick vanilla glaze settles into the ridges, giving you just enough sweetness without ever feeling heavy.

Ingredients

2 ½ cups (315 g) all-purpose flour: spooned and leveled, not scooped.
2 ½ tsp baking powder: make sure it’s fresh for a good rise.
½ tsp fine sea salt: balances the sweetness.
1 cup (226 g) unsalted butter, softened: room temperature for easy creaming.
2 cups (400 g) granulated sugar: sweet but not cloying.
4 large eggs, room temperature: cold eggs can curdle the batter.
1 tbsp pure vanilla extract: the real stuff makes a difference.
1 cup (240 ml) buttermilk, room temperature: adds tang and tenderness.
½ cup (90 g) rainbow sprinkles: jimmies-style, not nonpareils.

For the Glaze

1 ½ cups (180 g) powdered sugar: sifted if lumpy.
2 to 3 tbsp milk: any kind works.
½ tsp vanilla extract: rounds out the flavor.
Extra sprinkles for topping: as many as feels festive.

Variations / Substitutions

Make it dairy free: Swap the butter for a good vegan stick butter and use a plant-based milk with 1 tbsp lemon juice in place of buttermilk.
Chocolate glaze: Replace the vanilla glaze with a quick mix of 1 cup powdered sugar, 3 tbsp cocoa powder, and enough milk to drizzle.
Seasonal sprinkles: Use red and green for Christmas, pastels for Easter, or team colors for a game day cake.
Add a layer: Halve the recipe and bake in two 6-cup Bundt pans. Layer with a simple buttercream for a mini celebration cake.

For an even smaller treat, try vanilla sprinkle cupcakes with the same funfetti batter.

How to Make Easy Funfetti Birthday Bundt Cake

Step 1: Cream the Butter and Sugar

Preheat your oven to 350°F (180°C) and thoroughly grease a 10 to 12-cup Bundt pan with butter or nonstick baking spray. In a large bowl, beat the 1 cup softened butter and 2 cups sugar with an electric mixer until the mixture looks pale and fluffy, about 3 minutes. Scrape down the sides, then beat in the 4 eggs one at a time, mixing well after each addition. Stir in the 1 tbsp vanilla.

Whisk the 2 ½ cups flour, 2 ½ tsp baking powder, and ½ tsp salt together in a separate bowl. Add the dry ingredients to the butter mixture in three additions, alternating with the 1 cup buttermilk, starting and ending with the flour. Mix on low speed just until no dry streaks remain. The batter will be thick and smooth. Stop as soon as it comes together—overworking the flour is what turns a cake tough.

Step 2: Fold in the Sprinkles

Gently fold the ½ cup rainbow sprinkles into the batter with a spatula. Use a light hand and only a few strokes; you want them evenly distributed but not bleeding. If the colors start to streak, stop right away. A little marbling is fine, but a grey batter is something we all want to avoid.

Step 3: Bake the Cake

Pour the batter into your prepared pan and smooth the top with a spatula. Bake for 40 to 45 minutes, until a toothpick inserted near the center comes out clean or with a few moist crumbs attached. The cake will pull away from the sides slightly and feel springy when you press it gently. If the top browns too fast before the center is done, tent it loosely with foil for the last 10 minutes.

Step 4: Drizzle and Decorate

Let the cake cool in the pan for exactly 10 minutes, then invert it onto a wire rack to cool completely. While it cools, whisk the 1 ½ cups powdered sugar, 2 tbsp milk, and ½ tsp vanilla until smooth, adding an extra tablespoon of milk if needed for a pourable consistency. Once the cake is totally cool, pour the glaze slowly over the top so it drips down the sides. Immediately scatter more sprinkles over the wet glaze. Let it set for 10 minutes before slicing, and the first cut will show that soft, sprinkle-speckled crumb.

Tips for a Party-Ready Bundt Cake

Grease the pan with care: Use softened butter and a pastry brush to coat every crevice, then dust with flour and tap out the excess. Nonstick baking spray with flour also works well. Stuck-on cake is the fastest way to ruin the reveal.
Choose the right sprinkles: Jimmies (the long, soft cylinders) hold their shape and color. Avoid nonpareils, those tiny round balls that bleed red and blue streaks into the batter.
Slice with a serrated knife: A gentle sawing motion gives you clean, crumb-free pieces, especially through the sprinkles. A sharp chef’s knife can drag.
Room temperature matters: If the eggs or buttermilk are cold, the butter can seize up and turn the batter grainy. Pull them from the fridge an hour ahead.

Bake times vary by pan size. Here’s a guide:

Pan Size	Bake Time
6-cup	30–35 mins
10-cup	40–45 mins
12-cup	50–55 mins

Keeping Leftover Bundt Cake Fresh

Refrigerate: Store the glazed cake in an airtight container for up to 5 days. The crumb stays moist, though the glaze may soften slightly.
Reheating: A single slice warmed in the microwave for 10 to 15 seconds recaptures that fresh-from-the-oven tenderness. No need to thaw first.
Serve Cold: This cake is just as good straight from the fridge, where the butter firms up the crumb and the glaze gets a little crackly.

Frequently Asked Questions

Why did my sprinkles sink to the bottom?

The batter was too thin or you overmixed after adding them. Tossing the sprinkles with a teaspoon of flour before folding helps them stay suspended.

How do I prevent the cake from sticking?

A thorough greasing is key, but also avoid letting the cake cool in the pan longer than 10 minutes. After that, the sugars start to set and grab onto the pan.

What frosting can I use instead of glaze?

A simple vanilla buttercream works, but it will cover the ridges. A cream cheese glaze or a thin chocolate ganache keeps the shape while adding richness.

Can I make this without a mixer?

Yes. Use a sturdy wooden spoon and some elbow grease. Creaming the butter and sugar by hand takes closer to 5 minutes and a lot of arm work, but the cake will still turn out beautifully.

My Bundt pan is 9 inches. Will the batter fit?

A standard 10-cup pan is about 9 inches across. If yours holds less (check the bottom), pour in only enough batter to fill two-thirds full and bake any extra in a small loaf pan.