Peanut Butter Cake with Chocolate Mousse, Peanut Butter glaze, AND Peanut Butter Whipped Cream

Ingredients
 
For the cake:

2 cups all-purpose flour

1 cup granulated sugar

1 cup brown sugar, packed

1/2 teaspoon salt

1/2 cup buttermilk

2 large eggs (or 3 medium)

1 teaspoon baking soda

1 teaspoon vanilla

6 ounces unsalted butter

3/4 cup creamy peanut butter

1 cup boiling water

1 ½ cups Mini Reese’s Peanut Butter Cups, quartered

 

For the Peanut Butter Glaze:

1 can sweetened condensed milk

½ cup creamy peanut butter

1 tablespoon vanilla

¼ teaspoon salt

 

For the chocolate mousse:

1 ½ cups mini marshmallows

2 ounces unsalted butter

9 ounces bittersweet chocolate (minimum 70% cocoa solids) chopped into small pieces (I used a mix of Hershey’s Milk and Semi-Sweet Chocolate Chips and it was totally fine, don’t spend a fortune on chocolate here)

¼ cup hot water

1 cup heavy cream

1 teaspoon vanilla

 

For the Peanut Butter Whipped Cream:

1 cup heavy cream

1 heaping tablespoon creamy peanut butter

1 tablespoon vanilla

2 tablespoons caster sugar

 

12 Reese’s Peanut Butter Cups for garnish, chopped (I used the regular size, not mini…but either will do)

 

Directions

 

*my recommendation is the following:  first bake the cake.  This can be done days ahead of time.  Simply cut into squares and store in an air-tight container until ready to assemble.  The mousse can be made the same day at the cake (also kept in an air-tight container or a bowl covered with plastic wrap).  The day you’re ready to assemble the trifle, prepare the glaze and whipped cream.  However, keep in mind the trifle needs to sit over night before serving so the flavors can blend together and get happy.  Please don’t skip this step, it makes all the difference.

 

For the cake, preheat oven to 350 degrees Fahrenheit. 

 

Grease a jelly roll pan or sheet pan with butter or vegetable shortening.  I use a sandwich baggie as a glove to make this step easy.

 

In a large bowl, sift the flour.  Add the sugars and salt.  Whisk to combine and set aside.

 

In a small bowl, whisk together the buttermilk, eggs, baking soda, and vanilla.  Set aside.

 

In a medium saucepan, melt together the butter and peanut butter.  Add the hot water and mix to combine.  Remove from heat.

 

Pour the peanut butter mixture over the flour/sugar mixture and stir until halfway combined.  Pour in the buttermilk mixture and stir until just combined, but don’t over mix.

 

Gently fold in chopped Peanut Butter Cups.

 

Pour mixture into prepared pan and bake for about 20 minutes or until a toothpick inserted into the middle comes out clean.  Remove from oven and let cool completely on wire rack.

 

For the mousse, place the marshmallows, butter, chocolate, and water in a medium sized heavy saucepan.

 

Melt over medium heat, stirring often until smooth and no lumps remain.  Remove from heat and let cool to almost room temperature (bowl can be placed in the fridge/freezer to speed this step up).

 

Once the chocolate mixture has cooled down, whip the cream and vanilla until stiff peaks form. 

 

Gently fold the whipped cream into the chocolate mixture.  DO NOT STIR!  You must fold it otherwise you will lose the air you have just incorporated into the cream.  If you find you are left with lumps of cream, gently break them with the tip of your spatula in a zig-zag motion.  Don’t worry if they don’t totally disappear, it won’t even be noticeable once the mousse is added to the trifle.

 

Tightly wrap the mousse with plastic wrap and keep refrigerated until you’re ready to assemble.

 

To prepare the glaze, combine the sweetened condensed milk, peanut butter, and salt in a small saucepan.  Heat until the peanut butter is melted and the mixture is smooth.  Remove from heat and stir in the vanilla.  Set aside.

 

To prepare the trifle, place large squares of cake on the bottom of your dish, compacting down with the back of a spoon (or your fingers) to get a thick, some-what dense layer. 

 

Next layer HALF of the peanut butter glaze over the cake using a spatula to help spread evenly.  If you find it’s too thick to spread, microwave for about 20 second or until it’s more fluid.  Refrigerate dish until the glaze layer has firmed up, about half an hour (this step helps to keep nice, even layers.  Otherwise the weight of the layers above will make them sink together).

 

Remove dish from the fridge and spoon entire bowl of chocolate mousse over the peanut butter glaze.

 

Add another thick layer of cake to cover the chocolate mousse, gently pressing down to compress.  However don’t push too hard you don’t want the cake to sink into the mousse.

 

Pour the remaining peanut butter glaze over the cake, re-heating if it’s gotten too thick.  Cover dish with plastic wrap and place in the fridge for about 30 minutes to firm up.

 

Meanwhile, prepare the peanut butter whipped cream.  Place the heavy cream in the bowl of a stand up mixer (hand mixer ok) and beat on high until soft peaks form.  Turn off mixer and add the vanilla, sugar, and peanut butter.  Beat on high until stiff peaks form.  Be sure not to over beat or the mixture will separate (due to all the extra fat from the peanut butter). 

 

Remove dish from fridge and spoon the whipped cream onto the center and spread out evenly.  I left a small gap from the whipped cream to the edge of the bowl to place the chopped Peanut Butter Cups for garnish.

 

Refrigerate overnight and serve immediately. 

Enjoy!

 

Cake recipe adapted from The Pioneer Woman

Mousse recipe courtesy of Nigella Express