Why You Must Make This Cake

• If you love Reese’s and the delightful combination of chocolate and peanut butter, you’ll go crazy for this dessert!
• With a fudgy brownie base, mini Reese’s cups, and two kinds of mousse, it’s truly extraordinary.
• Even those in my family who typically shy away from peanut butter desserts enjoyed a slice!

In my home, there’s a playful rivalry not just over sports teams but also over peanut butter preferences. While I absolutely adore peanut butter desserts, my husband prefers it solely in sandwiches and turns his nose up at peanut butter cookies and Rice Krispie treats. Thankfully, my oldest son and daughter are on my team, while the youngest sides with Dad. Consequently, I save my most decadent peanut butter recipes for special occasions or pitch-in dinners.

Ingredient Notes

• Kitchen Staples: Water, Powdered Sugar, Butter, Semisweet Chocolate Chips
• 1 Box Brownie Mix: Or you can make my One Bowl Fudgy Brownies, baking for 35 minutes.
• 8 ounces Reese’s Minis: Reserve some for garnishing on top.
• Powdered Gelatin: Look for the Knox brand in the Jello aisle.
• Reese’s Peanut Butter Chips: Found in the baking aisle among the other chocolate chips.
• Heavy Cream: Choose something with 36% butterfat for best results.
• Creamy Peanut Butter: I typically use Jif, but any brand will do. Avoid natural peanut butter as it won’t provide the right texture.

Expert Tips

• Use a springform pan for easy assembly. Its removable sides are perfect for layered desserts.
• Make sure your brownie layer is completely cool before continuing to the next steps.
• PRO-Tip: Both the peanut butter mousse and chocolate mousse require about 2 hours of chilling time. While the process may seem straightforward, it relies heavily on waiting for things to cool and set, so consider making it the day before serving.
• PRO-Tip: An offset spatula is incredibly useful for spreading the mousse evenly and achieving smooth, level layers.
• Store the mousse cake in the refrigerator until just before serving due to its perishable nature. It can last up to 4 days in the fridge, but don’t let it sit at room temperature for over two hours.
• For storage, you can keep it in the springform pan covered with plastic wrap or foil, or wrap it directly on the serving plate to create an airtight seal.

Even with everyone feeling stuffed after our book club pitch-in dinner, there was still room for this luscious dessert. There were many “oohs” and “aahs” as I served up slices of this mousse cake. The biggest surprise came when my husband and youngest son each enjoyed a slice the following night! They were well aware of the peanut butter mousse but both licked their plates clean. Baby steps indeed!

Instructions

1. Begin by baking the brownies in a greased and parchment-lined 9-inch springform pan. Allow to cool completely, then carefully remove the brownie from the pan.
2. Place the cooled brownie back into the springform pan. Line the sides with parchment paper that extends above the pan, creating a mold for the mousse layers.
3. Sprinkle the Reese’s pieces evenly over the brownie layer.

Peanut Butter Mousse Layer

1. To prepare the peanut butter mousse, sprinkle the gelatin over the water in a bowl and let it sit undisturbed for about 5 minutes.
2. Heat ¾ cup of heavy cream in the microwave until boiling. Stir in the gelatin until well combined.
3. In a heatproof bowl, add the peanut butter chips and pour the hot cream mixture over them. Let sit for about a minute, then stir until smooth.
4. Allow the mixture to cool for about 5 minutes. Meanwhile, in a separate bowl, whip 1½ cups of heavy cream on high speed and add the powdered sugar until stiff peaks form.
5. Gradually fold the whipped cream into the peanut butter mixture until fully combined.
6. Spread this creamy mixture over the brownie and Reese’s layer.
7. Chill for at least 2 hours.

Chocolate Mousse Layer

1. Repeat the gelatin process: sprinkle it over the water and let it sit for about 5 minutes.
2. Microwave ¾ cup of heavy cream until boiling, then mix in the gelatin until dissolved.
3. Place the chocolate chips in a bowl and pour the hot cream mixture over them. Let sit for a few minutes before whisking until smooth.
4. Next, whip 1½ cups of heavy cream with the powdered sugar until stiff peaks form.
5. Gently fold the whipped cream into the cooled chocolate mixture until fully combined.
6. Pour the chocolate mousse layer over the peanut butter mousse layer and return to the refrigerator for an additional 2 hours or until set.

Final Touches

1. Once the mousse layers are firm, carefully remove the sides of the springform pan and the parchment collar.
2. To prepare the peanut butter frosting, beat together the creamy peanut butter, softened butter, and powdered sugar until whipped and fully blended.
3. Pipe decorative rosettes using the peanut butter frosting around the edge of the cake, topping each rosette with a mini Reese’s cup for a beautiful finish.

Frequently Asked Questions