Delicious rich and moist chocolate cake that’s met with a smooth peanut butter mousse filling that’s covered with more chocolate.
The cake is topped with a chocolate ganache and our favorite, Reese’s! With each bite, you get the perfect blend of moist chocolate cake and peanut butter. The ultimate flavor combination that is to die for.
I first made this cake for my husband who loves all things peanut butter. It was a no-brainer that chocolate pairs so well with peanut butter. I wanted to impress my husband (obviously). I enhanced the cake’s flavor with a smooth ganache. Then, I decorated it using leftover frosting and Reese’s to tie it all in. This has now become traditional birthday cake for my husband every year, and it’s something I get enjoyment from too 🙂
Why You’ll Love this Recipe
It’s FULL of chocolate and peanut butter!
Where are ALL the chocolate and peanut butter lovers?! We know that chocolate peanut butter combination goes so well together. We see it all the time in candy, brownies, cookies, and now we have this delicious cake. The peanut butter adds a creamy taste to the cake to help balance out the richness of the chocolate. If you’re worried about the sweetness of the cake, you can opt out and not include the ganache. However, I think that would be a huge mistake.
Perfect for all occasions
You don’t need a special occasion or day to enjoy this delicious cake. Although this cake can be time consuming, it’s well worth it. This cake is for chocolate, peanut butter, and dessert lovers. If it was legal to eat this for breakfast, lunch, and dinner, I would.
Make ahead friendly
All components of this cake can be prepped ahead of time, making the day of assembly stress-free and easy! Once cooled, wrap the chocolate cake layers with plastic wrap. Then you can place them in the freezer for up to 3 months.
The chocolate frosting can be made 2–3 days in advance and stored in an airtight container in the refrigerator. When you’re ready to use it, let it sit at room temperature for one hour until softened. Rewhip with a mixer for 1–2 minutes to bring back its smooth, fluffy texture. If needed, add a splash of milk (1 teaspoon at a time) to loosen it to the perfect spreading consistency.
The peanut butter mousse is perfect for prepping in advance. You can make it up to 24 hours ahead and store it covered in the refrigerator. As it chills, it naturally thickens into the ideal spreadable consistency for layering in the cake.
Let’s Start Baking!
Double Chocolate Cake with Peanut Butter Mousse Filling
Ingredients
Chocolate Cake:
- ¾ cup unsalted butter, room temperature (170 g)
- 1½ cups white granulated sugar (300 g)
- 3 eggs, room temperature
- ½ cup sour cream, room temperature (120 g)
- ½ cup whole milk, room temperature (120 g)
- 1 cup hot water or hot coffee (240 ml)
- 2¼ cups all purpose flour spooned and leveled (270 g)
- 1 cup unsweetened cocoa powder (85 g)
- 1½ tsp baking powder
- 1½ tsp baking soda
- 1 tsp salt
- 2 tsp vanilla extract
Peanut Butter Mousse Filling:
- 1/2 cup white chocolate chips
- 1/4 cup creamy peanut butter
- 1/4 cup heavy cream (60 ml)
- pinch of salt
- 1/3 cup heavy whipping cream (88 ml)
- Chocolate Frosting:
- 3/4 cup unsalted butter, room temperature (170 g)
- 2 ½ cups powdered sugar
- ½ cup unsweetened cocoa powder
- 4 tbsp milk
- 1 tsp vanilla extract
- pinch of salt
Chocolate Ganache:
- ½ cup heavy cream (120 ml)
- 4 ounces semi sweet chocolate chips
- 6 Reese’s, cut in half
Instructions
Chocolate Cake:
- Preheat oven to 350°F. Grease and line two 8-inch round pans with parchment.
- In a small bowl, whisk the hot water into the cocoa powder until smooth. Set aside to cool slightly.
- Using a stand mixer, beat together the unsalted butter and sugar on medium-high for 2–3 minutes until light and fluffy. Beat in eggs, one at a time. Mix in sour cream, milk, and vanilla until well combined.
- Add dry ingredients to the batter and mix just until combined. Add the bloomed cocoa mixture and mix until smooth, make sure you don’t over-mix the batter.
- Divide evenly between pans (about 700g for each pan). Bake for 30-35 minutes, until a toothpick inserted comes out with moist crumbs. Cool for 10 minutes in pans, then turn out and cool completely before filling.
Peanut Butter Mousse:
- In a microwave-safe bowl, microwave the heavy cream in 30 second intervals until steaming/simmering (you don't want to have it boil).
- Once simmering, place your white chocolate chips and creamy peanut butter and allow to sit for 5 minutes. After 5 minutes, whisk until fully combined and smooth. Set aside while making your whipped cream.
- In a separate chilled bowl, whip the heavy whipping cream until soft peaks form. Fold the whipped cream into peanut butter mixture in two seperate batches. Continue to gently fold until the mousse is light and airy.
- Place the mousse in the refrigerator for at least 20 minutes to firm up slightly.
Chocolate Buttercream Frosting:
- In a large mixing bowl, beat the butter on medium speed for 2–3 minutes until light and fluffy. Gradually add the powdered sugar and unsweetened cocoa powder to the bowl. Mix on low speed.
- Once the mixer is on low, gradually add the milk, vanilla extract, and a pinch of salt. Increase speed to medium until fully combined.
- When fully combined, increase speed to high for 2-3 minutes until light, fluffy, and smooth in consistency.
Chocolate Ganache Drip:
- In a microwave-safe bowl, microwave the heavy cream in 30 second intervals until steaming/simmering (you don't want to have it boil).
- Add chocolate chips to the heavy cream, allow it to sit for 5 minutes. After 5 minutes, whisk until fully combined, smooth, and glossy. Allow to sit for at least 30 minutes to thicken and cool.
Assembly:
- Place the first cooled cake layer on your cake board. Using a serrated knife or cake leveler, carefully trim the domed top so the layer is flat. Repeat with the second layer.
- To the first layer, add a thin layer of buttercream followed by a buttercream dam around the outside of the cake. Spoon the chilled PB mousse onto the center of the bottom cake layer.
- Using an offset spatula, spread it evenly, leaving about ½ inch from the edge to prevent overflow. Gently place the second cake layer on top.
- Spread a thin layer of chocolate frosting over the top and sides of the stacked cake to seal in crumbs. Chill the cake for 15–20 minutes until the crumb coat is firm.
- Apply a thicker layer of chocolate frosting over the top and sides, reserving about 1 cup for piping frosting on the top if desired. Smooth with an offset spatula or bench scraper for a clean finish.
- Pour the ganache over the center of the cake and gently spread toward the edges, letting some drip down the sides naturally. Use a spoon or offset spatula to control drips for a neat look.
- Using a 1M piping tip, create 8 swirls evenly around the cake. Cut 6 Reese’s in halves and arrange them in between each swirl.
- Chill the finished cake for at least 20–30 minutes to allow mousse and ganache to set.
Notes
- When serving the cake, run your sharp knife under hot water for 20-30 seconds then wipe off before cutting for a smooth slice. Repeat in between each cut.
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