Moist Marble Bundt Cake with Ganache Glaze

There’s something irresistibly nostalgic about a marble cake — that perfect swirl of rich chocolate and buttery vanilla intertwined in every slice. This Moist Marble Bundt Cake takes that classic flavor combination and transforms it into something truly special. Baked to perfection in a bundt pan and finished with a glossy ganache glaze, it’s an elegant dessert that’s as beautiful as it is delicious.

The secret behind its tender crumb and incredible flavor lies in three key ingredients: real butter, sour cream, and bittersweet chocolate. Together, they create a cake that’s rich, moist, and deeply satisfying without being overly sweet.

Whether you bake it in mini bundt molds for individual portions or in a full-sized pan for a stunning centerpiece, this marble cake is guaranteed to impress.

Why You’ll Love This Cake

Perfectly moist texture thanks to the addition of full-fat sour cream.
Beautiful marbled design made easily with a simple swirl technique.
Rich and buttery flavor balanced by deep chocolate notes.
Versatile presentation — bake it as mini bundts, a large bundt, or even a loaf.

Ingredients

For the Cake:

½ cup unsalted butter, slightly cooler than room temperature
1 cup granulated sugar
2 large eggs, at room temperature
⅔ cup full-fat sour cream
2 teaspoons vanilla extract
1½ cups all-purpose flour
1 teaspoon baking powder
½ teaspoon salt
3 ounces bittersweet chocolate, melted and cooled
2 teaspoons unsweetened cocoa powder, sifted

For the Ganache Glaze (optional but highly recommended):

½ cup heavy cream
4 ounces semisweet chocolate, finely chopped
1 tablespoon unsalted butter (for shine)

Instructions

Preheat the Oven
Preheat your oven to 350°F (175°C). Grease and flour a 12-cup mini bundt pan or a standard bundt pan, tapping out any excess flour to prevent sticking.
Cream the Butter and Sugar
In a large mixing bowl or stand mixer fitted with a paddle attachment, beat the butter and sugar together on medium-high speed until light and fluffy, about 3–4 minutes. This step builds air into the batter, giving the cake its soft crumb.
Add the Eggs
Lightly whisk the eggs in a small bowl. Add them to the butter mixture a little at a time, beating well after each addition. This ensures a smooth, even texture without curdling.
Mix in Sour Cream and Vanilla
In a separate bowl, combine the sour cream and vanilla extract. Add this mixture to the batter and beat just until incorporated.
Combine the Dry Ingredients
In another bowl, sift together the flour, baking powder, and salt. Add these dry ingredients to the wet mixture on low speed, mixing only until combined. Be careful not to overmix — this helps keep the cake tender.
Create the Chocolate Batter
Scoop out about one-third of the vanilla batter into a separate bowl. Stir in the melted bittersweet chocolate and cocoa powder, mixing until smooth and evenly colored.
Assemble the Marble Pattern
Spoon each batter into two separate piping bags (or use a spoon if you prefer). Pipe or spoon alternating layers of vanilla and chocolate batter into each bundt mold or the larger pan.
Swirl the Batter
Using a skewer or thin knife, gently swirl the two batters together to create a marbled effect — just a few swirls are enough. Overmixing will blend the colors too much.
Bake the Cake
Bake for about 20–25 minutes for mini bundts, or 40–45 minutes for a large bundt, until a toothpick inserted in the center comes out clean.
Cool Completely
Allow the cakes to cool in the pan for 30 minutes, then carefully invert onto a wire rack to cool completely before glazing.

To Make the Ganache Glaze

In a small saucepan, heat the heavy cream over medium heat until just simmering (do not boil).
Remove from heat and pour over the chopped chocolate in a heatproof bowl. Let it sit for 2 minutes to melt.
Add the butter and stir until smooth and glossy.
Once the cakes are cool, dip or drizzle the ganache over the tops and let it set before serving.

Tips for the Best Marble Bundt Cake

Room-temperature ingredients ensure a smooth, even batter.
Use quality chocolate — bittersweet or dark works best for a rich flavor.
Don’t over-swirl — you want clear streaks of chocolate and vanilla.
Add flair: Garnish with shaved chocolate, powdered sugar, or a light drizzle of white chocolate for contrast.

Storage

Store the cake in an airtight container at room temperature for up to 3 days or refrigerate for up to 5 days. It also freezes beautifully — wrap tightly in plastic wrap and foil, then thaw overnight before serving.