Chocolate Peanut Butter Swirl Bundt Cake
This chocolate peanut butter bundt cake has a deep, fudgy crumb and a ribbon of creamy peanut butter that settles into the center as it bakes. Every slice shows off the swirl, and a glossy chocolate glaze ties it all together.
It comes together with one bowl for the batter and a quick filling you can stir in a few minutes. No stand mixer needed, and the whole thing looks far more impressive than the effort it takes.
Why This Cake Works
The cake stays incredibly moist because of hot coffee and oil. The crumb is tight but tender, and it tastes deeply of chocolate, not just cocoa powder.
The peanut butter filling is sweetened just enough to remind you of a peanut butter cup, and it stays soft and creamy even after baking. Because it’s baked in a bundt pan, you get that swirl in every bite without any layering or frosting.
Ingredients
- 2 cups (250g) all-purpose flour: spoon and level for accuracy
- 3/4 cup (63g) unsweetened cocoa powder: natural cocoa, not Dutch-process, for the best lift
- 1 3/4 cups (350g) granulated sugar
- 1 1/2 tsp baking soda
- 1 tsp baking powder
- 1 tsp fine sea salt
- 2 large eggs, room temperature
- 1 cup (240ml) buttermilk, room temperature: full-fat if you can
- 1/2 cup (120ml) vegetable oil: or another neutral oil
- 2 tsp vanilla extract
- 1/2 cup (120ml) hot brewed coffee: or hot water, deepens the chocolate flavor
- For the peanut butter filling:
- 8 oz (226g) cream cheese, softened
- 3/4 cup (190g) creamy peanut butter: a no-stir, sweetened brand like Jif or Skippy works best
- 1/3 cup (67g) granulated sugar
- 1 large egg, room temperature
- 1 tsp vanilla extract
- For the chocolate glaze:
- 4 oz (113g) semisweet chocolate, chopped
- 1/2 cup (120ml) heavy cream
- Pinch of sea salt
Variations / Substitutions
- Swap the nut butter: almond butter or cashew butter work, but the swirl will be less sweet.
- Add chocolate chips: fold 1/2 cup mini chocolate chips into the chocolate batter for extra bursts.
- Make it mocha: stir 1 tablespoon espresso powder into the hot coffee before adding to the batter.
- Dairy-free option: use a vegan butter stick in the filling, replace buttermilk with 1 cup unsweetened almond milk plus 1 tablespoon lemon juice, and use a dairy-free cream alternative for the glaze.
- Skip the glaze: a dusting of powdered sugar right before serving is just as good if you prefer less sweetness.
For another chocolate classic, try the Dark Chocolate Fudge Cake.
How to Make Chocolate Peanut Butter Swirl Bundt Cake
Step 1: Mix the Chocolate Batter
Preheat the oven to 350°F (175°C). Grease a 10- or 12-cup bundt pan generously with butter, then dust with cocoa powder to keep the dark cake from showing any flour spots. In a large bowl, whisk together the 2 cups flour, 3/4 cup cocoa powder, 1 3/4 cups sugar, 1 1/2 teaspoons baking soda, 1 teaspoon baking powder, and 1 teaspoon salt. Add the 1 cup buttermilk, 1/2 cup oil, 2 eggs, and 2 teaspoons vanilla. Beat with a hand mixer on low until just smooth, scraping the bowl once. Pour in the hot coffee and mix until the batter is uniform, about 30 seconds. It will look thin, almost like a heavy cream, and that is exactly right.
The batter at this stage should be free of dry streaks but still glossy. Overmixing now can make the cake tough, so stop as soon as the flour disappears.
Step 2: Beat the Peanut Butter Filling
In a medium bowl, beat the 8 ounces cream cheese, 3/4 cup peanut butter, and 1/3 cup sugar with clean beaters until smooth and no lumps remain, about 1 minute. Beat in the 1 egg and 1 teaspoon vanilla just until combined. Scrape the filling into a piping bag or a zip-top bag and set it aside.
The filling should be thick enough to hold its shape but soft enough to pipe easily. If it feels too stiff, let it sit at room temperature for a few minutes while you get the pan ready.
Step 3: Fill the Pan and Swirl
Pour half of the chocolate batter into the prepared bundt pan, spreading it evenly with a spatula. Snip a half-inch corner off the bag of filling and pipe a ring of peanut butter filling over the batter, keeping the ring about an inch away from the edges of the pan. Top with the remaining chocolate batter, covering the filling completely. Insert a table knife into the batter and draw a gentle figure-eight pattern through the whole pan, circling just 3 or 4 times.
You want distinct streaks, not a blended muddle. Over-swirling will mix the two batters and you will lose that pretty ribbon you worked to create. The knife should feel like it is carving soft ribbons, not stirring.
Step 4: Bake Until Set
Set the pan on the middle oven rack and bake for 50 to 55 minutes, or until a toothpick inserted into the cake (avoiding the filling lane) comes out with a few moist crumbs. The top will spring back when lightly pressed, and the edges may have pulled slightly from the sides of the pan. Let the cake cool in the pan on a wire rack for exactly 10 minutes, then invert it onto the rack to cool completely.
Be patient about the cooling step. If you try to glaze a warm cake, the glaze will slide right off and pool around the plate. The crumb also finishes setting as it cools, so cutting in too soon can tear the swirl.
Step 5: Glaze the Cake
While the cake finishes cooling, make the glaze. Heat the 1/2 cup heavy cream in a small saucepan or in a microwave-safe bowl until it just begins to simmer. Pour it over the chopped chocolate and the pinch of salt, let it sit for 2 minutes, then stir gently until smooth and glossy. Pour the glaze over the completely cooled cake, letting it drip down the sides. Let the glaze set for about 30 minutes, then slice and serve.
The set glaze will be shiny and just firm enough to hold its shape. Serve slices at room temperature so the cake crumb stays tender and the peanut butter swirl stays soft.
A Few Notes Before You Start
- Grease that pan well. Bundt pans have lots of crevices. Use softened butter and a pastry brush to coat every nook, then dust with cocoa powder and tap out the excess. This keeps the cake from sticking and avoids white flour marks on a dark cake.
- Limit your swirl passes. Three or four gentle figure-eight passes are plenty. The goal is ribbons, not a homogenous batter.
- Room temperature ingredients matter. Cold eggs or cream cheese can cause the filling to seize and make it hard to pipe smoothly.
- Adjust the glaze if it thickens too much. If the glaze becomes too thick to pour, stir in a little extra warm cream, one teaspoon at a time, until it reaches a pourable consistency.
Bake times by pan size and material:
| Pan Size | Material | Bake Time |
|---|---|---|
| 10-cup | aluminum | 50-55 mins |
| 10-cup | nonstick/dark | 45-50 mins |
| 12-cup | aluminum | 55-60 mins |
| 12-cup | nonstick/dark | 50-55 mins |
Storing Leftovers
- Room temperature: cover the cake loosely and keep it on the counter for up to 2 days.
- Refrigerator: store covered in the fridge for up to 5 days. Let slices come to room temperature before serving for the best texture.
- Freezer: freeze the unglazed cake, tightly wrapped, for up to 3 months. Thaw overnight in the fridge and glaze just before serving.
What to Serve with Chocolate Peanut Butter Swirl Bundt Cake
A scoop of vanilla ice cream adds a cool, milky contrast to the dense chocolate crumb. If you want an extra hit of peanut butter, warm a little peanut butter in the microwave and drizzle it over the slices just before serving. A glass of cold milk on the side never hurts.
Frequently Asked Questions
Can I use natural peanut butter?
It can work, but natural peanut butter is oilier and thinner, so the swirl may separate during baking. If it’s what you have, stir it thoroughly before measuring and expect a slightly looser filling.
Why did my cake stick to the pan?
Bundt pans grab even when you grease them well. Butter every crevice carefully and dust with cocoa powder, not flour. Let the cake cool exactly 10 minutes before inverting; any longer and it can start to re-stick.
Can I skip the coffee?
Yes, use hot water instead. The coffee does not leave a coffee taste, it simply deepens the chocolate flavor. Hot water will still give you a moist cake.
How long does the glaze take to set?
About 30 minutes at room temperature. You can speed it up by placing the glazed cake in the refrigerator for 15 minutes, but serve it at room temperature for the best flavor and texture.
Chocolate Peanut Butter Swirl Bundt Cake Recipe
Ingredients
Method
- Preheat the oven to 350°F (175°C). Grease a 10- or 12-cup bundt pan with butter and dust with cocoa powder.
- Whisk together flour, cocoa, 1 3/4 cups sugar, baking soda, baking powder, and salt in a large bowl. Add buttermilk, oil, 2 eggs, and 2 tsp vanilla. Beat until smooth, then stir in hot coffee until just combined.
- In another bowl, beat cream cheese, peanut butter, and 1/3 cup sugar until smooth. Beat in the remaining egg and 1 tsp vanilla. Transfer to a piping bag.
- Pour half the chocolate batter into the pan. Pipe a ring of filling over it, then top with remaining batter. Swirl 3–4 times with a knife.
- Bake for 50–55 minutes, until a toothpick comes out with moist crumbs. Cool in the pan 10 minutes, then invert onto a rack to cool completely.
- Heat cream until simmering, pour over chocolate and salt, let sit 2 minutes, then stir smooth. Pour over the cooled cake, let set 30 minutes, and serve.
