Chocolate Peanut Butter Mousse Cake Revisited

I can never quite decide how I want to make this cake…

There are no written laws, right? That’s why baking is so gosh darn fun.

Obviously, this cake is all about the PB and Choc. It’s that simple. And fattening.

There are so many ways to make it sinful. Add ganache or fudge frosting. Chop up some Reese’s PB Cups for the top.

Every time I make it, the components are the same, but I shake it up a little. Never exactly the same twice. This time I added the PB cups. And I think I will every time.

This year, because it was my dear friend’s cake I was making, I wanted to make sure I didn’t mess it up. (When I’m pregnant, my baking is very unpredictable.)

I had an idea I wanted to try. I wanted to doctor a cake mix because I knew if all else failed, the cake would at least be okay. (Yes, I use cake mixes occasionally.)

It worked out really, really well. It tasted great.

Doctored Chocolate Cake
original recipe


For cake:
1 German Chocolate Cake mix (Duncan Hines is the one I used)
3 heaping Tbsp. cocoa powder
1 stick butter, cold and cut into 8 pieces (for food processor directions) OR melted (for mixer)
3 eggs
1 1/4 cups milk

For Peanut Butter Mousse:
2 cups peanut butter (not natural)
8 oz. cream cheese
1 cup powdered sugar
1 tsp. vanilla
1 cup heavy cream, chilled

For Fudge Icing:
1 stick butter
4 heaping Tbsp. cocoa powder
2-3 cups powdered sugar (may not need all of it)
1/2 cup heavy cream


For cake:
Preheat oven to suggested temperature on cake mix package–usually 350 degrees.

Grease the cake pans and dust with cocoa powder. (I used 8″ by 3″ round pans.)

Food processor directions:
Place the cake mix and cocoa powder in the bowl of an 11-cup (or larger) food processor.

Scatter the cold butter over the cake mix. Place top on food processor. Pulse until butter is completely incorporated into the cake mix. (It will look sort of like cornmeal–well, not really, but that’s what all the recipes say when you cut the butter into the dry ingredients for biscuits, etc. No large pieces of butter should remain.)

Add the eggs and milk. Process for about 1 minute. The cake mix should be thick with no lumps.

Mixer directions:
Place all the ingredients in a large bowl and mix according to package directions.

Divide batter between the cake pans. Bake for recommended time according to package directions.

When cakes are fully baked, let them cool for about 10 minutes in the pan. Run a thin knife around the edges to loosen and transfer the cakes to a wire rack to finish cooling.

For Peanut Butter Mousse:

Using an electric mixer, beat the peanut butter and cream cheese. Add the powdered sugar and vanilla. Beat until combined.

It will be thick!

Clean the beaters and beat the heavy cream to soft peaks.

Fold the whipped cream into the peanut butter in two additions. (The purpose of the first addition of cream is to lighten the mousse a bit. You don’t want it to deflate!)

(first addition)

(after second addition)

Chill until ready to assemble the cake.

For Fudge Icing:
Place the butter in a large bowl and microwave for 1 minute, or until melted. Stir in the cocoa powder. Using an electric mixer, beat in part of the powdered sugar and a few tablespoons of the heavy cream. Add more powdered sugar and cream until icing is at a spreadable consistency.

To assemble the cake:
Split the cake layers horizontally–depending on how many layers you want to use. For this cake, there were two 8″ rounds that I split into half horizontally to create 4 layers of cake and three layers of filling.

Pipe or spread 1/4 of the PB mousse on the bottom layer. Top with next cake layer. Repeat with mousse and cake layers 2 more times, ending with piping or spreading the top most layer with the last of the mousse.

Frost the sides of the cake with the fudge icing. Garnish the cake with chopped peanut butter cups and/or chocolate shavings, if desired.

Enjoy it with a scoop of vanilla ice cream, or a huge glass of milk.

18 Responses to “Chocolate Peanut Butter Mousse Cake Revisited”

  1. Kristin March 22, 2008 at 8:27 pm #

    That looks delicious. And I am secretly glad to know that you occasionally use a cake mix. Me too. in fact, I used one today (with some adjustments) for Oliver’s birthday cake. I always worry aboutmy baking when pregnant. Glad to know I am not alone :)

  2. diva March 23, 2008 at 1:23 pm #

    i love peanut butter and chocolate! this is the best cake ever.

  3. michelle @ the smackdown March 23, 2008 at 4:09 pm #

    that’s pretty much exactly how i made peanut butter mousse, and i can vouch that it’s one of the best things in the whole entire world.

  4. Kevin March 23, 2008 at 5:30 pm #

    That cake looks so good!

  5. Deborah March 23, 2008 at 6:49 pm #

    Gorgeous cake!

  6. culinography March 23, 2008 at 7:58 pm #

    Now THAT’S a beautiful cake. YUM.

  7. A. Grace March 24, 2008 at 8:19 am #

    chocolate and peanut butter are obviously a match made in heaven!
    i suspect that i’d be tempted to eat that peanut butter mousse by the spoonful and not much of it would actually make it to the cake…

  8. Wendy March 24, 2008 at 1:05 pm #

    This cake was absolutely FABULOUS…better than that… I’m still dreaming of it! The Mousse and frosting were the most mouth watering combination, better than any bakery I’ve found! The pictures don’t do it justice (and they are awesome pictures)You are simply amazing! Thank you for making my birthday cake… this cake is the best one I’ve EVER had! You have a gift my friend!

  9. Jenn March 24, 2008 at 3:14 pm #

    So pretty and looks like it would taste so incredible!

  10. Nancy March 24, 2008 at 4:46 pm #

    wow. I want to make that for my own birthday, but I’ll have to wait until December. I’d best find another occasion to celebrate.

  11. sara March 24, 2008 at 5:58 pm #

    are you kidding me? that thing looks insanely delicious.


    how do you get your food photos so perfect?

  12. laura March 26, 2008 at 2:56 am #

    You CANNOT be in Utah for my birthday this year. I NEED that cake!

  13. Patricia Scarpin March 27, 2008 at 7:57 pm #

    This is a sinful cake! With chocolate and peanut butter, who can say no?

    Your photos are beautiful!

  14. ambrosia ananas April 6, 2009 at 4:15 am #

    Thanks for the recipe! I just used the mousse in a cake for my brother, and it was delicious.

  15. New momma April 10, 2009 at 9:27 pm #

    So I stumbled upon your blog from another blog that I follow. I am so glad I did! This looks so fantastic. I am going to make it this weekend for a church get together. Again I can’t wait! Thanks for sharing it with us.

  16. New momma April 20, 2009 at 12:19 pm #

    this was a big hit! i loved, loved, loved it. as did the people i shared it with. thanks for sharing it. i will be making this again!

  17. Jordan Tickle January 31, 2015 at 10:23 pm #

    I didn’t make the cake or frosting – was looking for a peanut butter mousse for my current chocolate cake recipe. Tried this (tweaked just a little here and there) and it’s DELICIOUS! Just what I was looking for. Thanks for sharing!

    • Lindsey Johnson February 2, 2015 at 11:14 am #

      So glad you enjoyed it! I appreciate the feedback too. :)

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