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Slice of chocolate peanut butter mousse on a white plate

Peanut Butter Chocolate Mousse Cake

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I whipped up this rich, luscious Peanut Butter Chocolate Mousse Cake for our annual summer book club dinner. Perfect for chocolate peanut butter fans!

A brownie layer was topped with chocolate and peanut butter mousses for an exquisite dessert!

Peanut Butter Chocolate Mousse Cake slice on a white dessert plate with a red handled fork

Peanut Butter Chocolate Mousse Cake

Ours is a house divided. No, I’m not referring to the Indiana University and Purdue University rivalry between my two sons. I’m talking about the peanut butter division. You see, I love peanut butter in desserts, but never straight up or in sandwiches. Blech.

The hubby is a fan of peanut butter sandwiches but gives a cold shoulder to peanut butter cookies, peanut butter Rice Krispie treats and all the other peanut butter sweets I adore. My oldest son and daughter are on my team, and our youngest agrees with dad. S

I save up my most decadent peanut butter creations for when I’m entertaining or bringing a dish to a pitch-in dinner. I saw this Peanut Butter Chocolate Mousse Cake on Hugs & Cookies XOXO and patiently waited for the perfect occasion to make it.

Peanut Butter Chocolate Mousse Cake on a basket weave serving plate

An Unprecedented Hit

Even though we were all stuffed to the gills with all the marvelous food at our book club pitch-in dinner, everyone had room for a  bit of dessert. There were swoons and groans and slices taken home after I dished up some slivers of this mousse cake.

The biggest surprise of all, though, was at home. Both Bill and Nick had a slice the next night. I told them they could scrape off the peanut butter mousse and focus on the chocolate elements. Well, they both licked their plates clean. Nick commented that the peanut butter flavor wasn’t overly intense, though he didn’t eat his peanut butter garnish. Baby steps!

Overhead view of Peanut Butter Chocolate Mousse Cake

Two Sweetie Pies

Thanks again to my lovely friend, Danielle, for another magnificent recipe! She is my go-to blogger for decadent treats. I promise you will love whatever you try from her blog!!! We share a recipe from each other’s sites every second Monday of the month.

Check out Danielle’s take on this Peanut Butter Chocolate Mousse Cake as well as her social media sites! Make sure to check out which of my recipes she made this month, too.

Hugs & Cookies XOXO – Facebook – Pinterest – Twitter – Instagram

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Peanut Butter Chocolate Mousse Cake photo and text collage
Peanut Butter Chocolate Mousse Cake

Peanut Butter Chocolate Mousse Cake

A decadent chocolate and peanut butter dessert.

Prep Time 1 hour
Cook Time 35 minutes
Total Time 1 hour 35 minutes
Yield 16 servings


  • 1 box brownie mix (I used my One Bowl Fudgy Brownies and baked for 35 minutes)
  • 8 ounces Reese's minis (reserve extras from bag for garnishing)

Peanut Butter Mousse Layer:

  • 1 1/8 teaspoon powdered gelatin
  • 1 1/2 tablespoons water
  • 9 ounces Reese's peanut butter chips
  • 2 1/4 cups heavy cream
  • 1/4 cup powdered sugar

Chocolate Mousse Layer:

  • 1 1/8 teaspoon powdered gelatin
  • 1 1/2 tablespoons water
  • 9 ounces semisweet chocolate chips
  • 2 1/4 cups heavy cream
  • 1/4 cup powdered sugar

Peanut Butter frosting for decorations:

  • 1/3 cup creamy peanut butter
  • 4 tablespoons butter, at room temperature
  • 1 cup powdered sugar


  1. Bake brownies in a greased and parchment lined 9-inch springform pan. Cool, then remove brownie from pan once cooled.
  2. Place cooled brownie back in the pan but also line the sides all the way around with parchment. It should extend above the pan to "hold" mousse.
  3. Sprinkle the Reese's on the brownie.

Peanut Butter Mousse

  1. To make peanut butter mousse, sprinkle gelatin on top of the water in a bowl and let sit 5 minutes.
  2. Heat ¾ cup cream in microwave till boiling and then add the gelatin. Whisk well.
  3. Place the peanut butter chips in a heatproof bowl and pour the cream over the chips. Let it sit a minute and stir until smooth.
  4. Cool for about 5 minutes. Meanwhile, beat 1½ cups heavy cream on high. Add powdered sugar and beat to stiff peaks.
  5. Slowly fold the cream into the peanut butter mixture.
  6. Spread this over the brownie and Reese's layer.
  7. Chill 2 hours.

Chocolate Mousse

  1. Again, in a bowl sprinkle the gelatin over the water. Let the gelatin dissolve for about 5 minutes.
  2. Microwave ¾ cup of the heavy cream to a boil.
  3. Add the gelatin mix to the hot cream and whisk.
  4. Place the chocolate chips in a bowl and pour the cream over them. Let sit a couple minutes and whisk until smooth.
  5. Meanwhile, beat 1½ cups heavy cream on high. Add the powdered sugar and beat to stiff peaks.
  6. Fold a little cream at a time into the cooled chocolate.
  7. Once all incorporated and smooth, pour this over the peanut butter mousse layer and chill another 2 hours or longer if not firm.

To finish the cake:

  1. Once firm, remove sides of the cake pan and parchment collar.
  2. To make peanut butter frosting, beat together peanut butter, butter and powdered sugar till whipped and creamy.
  3. Pipe on rosettes with peanut butter frosting. Top each rosette with a peanut butter cup.


Total time does not include the 5+ hours of cooling and chilling times.

Nutrition Information:



Serving Size:

1 slice

Amount Per Serving: Calories: 578Total Fat: 45gSaturated Fat: 24gTrans Fat: 1gUnsaturated Fat: 18gCholesterol: 85mgSodium: 188mgCarbohydrates: 43gFiber: 2gSugar: 36gProtein: 8g



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30 comments on “Peanut Butter Chocolate Mousse Cake”

  1. I can get my hubby to try lots of things but peanut butter isn’t one of them. So this would be for me only. I guess that’s good and bad!

  2. I’d be Switzerland in your family, Liz! Whether it’s a PB sandwich or an elegant Liz Berg PB Chocolate Mousse Cake, I’m in!!! P.s. Your book club is sooooo lucky =)

  3. Taking the chance of sounding like a broken disk/record – this cake looks absolutely HEAVENLY !!
    PB and chocolate is one my favorite combination ever.
    It’s not fair! It’s morning here and I’m already drooling…. 🙂

  4. LIZ OHMYGAWD. There’s chocolate mousse and pb mousse AND a brownie base??!!! pinningggggggggggg

  5. I thought this was going to be so much harder than it was! My whole family loved it! Thank you.

  6. This is the perfect compliment of chocolate to peanut butter for a dessert. I love peanut butter in any form. To have a decadent dessert like this is quite the treat, but love that the light fluffy mousse doesn’t make you feel that regretful feeling after you’ve eaten it!

  7. Liz, GIRRRL, you really can bake! This looks awesome!

  8. You know I am the world’s biggest chocolate and peanut butter fan, right. RIGHT???

  9. You make these most incredible desserts! Totally swooning over here!

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