Thursday, August 13, 2015

Peanut Butter S'mores Cake

Some people don't think my sister and I look much alike. She has more traits of my mom's side and I have more traits of my dad's side. But let me assure you, we are blood and proof is in the sweet tooth.

Case in point, I asked her what kind of cake she wanted for her birthday, and without hesitation, she said to me, "peanut butter s'mores." Not just a s'mores cake. Not just a regular peanut butter cake. A peanut butter s'mores cake! It was pure genius. This is literally the kind of cake I dream about! (I'll admit now, I'm a little biased toward this cake because I love peanut butter. Hmm, love might be talking about my relationship with peanut butter too lightly. I'm obsessed with the stuff. It's a main food group in my diet. I'll add it to just about any other food. Don't judge.) Anyway, with that secret out, I'll just say I was so excited to make this cake, and eat it with my sister! I knew we would both appreciate and savor every bite together!

To make this wildly rich and delicious cake, I looked up several different recipes and ultimately decided to piece together my own creation in order to get what I was looking for. You'll see I've used my go-to dark chocolate cake for the base. Its bittersweet flavor balances nicely with the more savory flavor of the peanut butter filling and the sweetness of the marshmallow frosting. And I love the baked in graham cracker layer! It adds a little contrast in texture to the rest of the cake. 

Oh, it's just so good... and like I said, seriously rich!

Also, I know this looks like a lot of steps, but don't let that scare you off from making this cake. When I'm making a cake with several steps like this, I spread out the baking over a few days. With this cake, I made the cakes a few days before the party and froze them until I was ready to assemble. Next, I made the peanut butter filling and ganache a day ahead. You can store the peanut butter filling and ganache in an air-tight container at room temperature for a day, or in the refrigerator for a few days. If you decide to stick them in the fridge, let both get to room temperature before you spread them on the cake during assembly. Finally, I made the marshmallow frosting day of and frosted the cake right away when it was finished.

Peanut Butter S'mores Cake

Yields: One 3-layer, 8-inch round cake 


Dark Chocolate Cake
2 ½ cups all-purpose flour
3 cups granulated sugar
1 cup Cacao Barry Extra Brute Cocoa Powder (or similar premium brand)
1 tablespoon baking soda
1 ½ teaspoon baking powder
1 ½ teaspoon salt
3 eggs, room temperature
1 ½ cups buttermilk, room temperature
1 cup hot water
¾ cup vegetable oil
1 ½ tablespoons pure vanilla extract

Peanut Butter Filling (used in Magnolia Bakery's Peanut Butter Pie)
1 cups heavy cream
1 1/2 cups cream cheese
3/4 cups peanut butter
1/2 cup confectioners' sugar (more if you want it on the sweeter side)
1/2 tablespoon pure vanilla extract

Brown Butter Graham Cracker Crust (from
18 large grahams (the rectangle)
1/2 cup sugar
1/2 teaspoon salt
12 tablespoons butter

Chocolate Ganache
1 cup heavy cream
8 ounces bittersweet chocolate, chopped or pieces

Marshmallow Frosting (from egg whites, room temperature
1/4 teaspoon salt
1/3 cup sugar
1 cup karo syrup
2 tablespoons water
1 tablespoon vanilla bean paste or clear vanilla extract


Brown Butter Graham Cracker Crust:
1. Melt the butter and cook on low until the butter is golden brown
2. In a food processor, pulse the graham crackers with the sugar and the salt until the crumbs are really fine. If you do not have a food processor, place the graham crackers in a large zip lock bag and use a rolling pin to smash and roll them into crumbs. Pour the crumbs into a medium bowl.
3. Pour the butter over the graham crackers and gently mix together until it is a uniform, damp crumb.
4. Prepare three 8" rounds with parchment paper rounds and non-stick baking spray.
Divide the graham cracker crumbs between two of the three prepared pans, pressing them down firmly with a spatula. Set aside.

Dark Chocolate Cake:
1. Preheat the oven to 350 degrees F. Prepare three 8” round cake pans (butter or spray, line bottom with parchment paper, butter or spray paper and dust with flour).
2. In a bowl of electric mixer, sift all dry ingredients. Set aside.
3. Combine eggs, buttermilk, coffee, oil and vanilla in a measuring cup and lightly beat with a fork.
4. Add wet ingredients to the dry ingredients, and mix on medium speed for two minutes. Batter will be thin. Scrape sides and mix for another 30 seconds. Divide batter evenly among prepared pans, carefully spreading the batter over the two pans with graham cracker. 
5. Bake for 25-27 minutes (you may need more time depending on your oven), until toothpick comes out almost clean. Cool on wire racks for 10-15 minutes, then gently invert onto racks until cooled completely.

Chocolate Ganache:
1. In a small pot, bring the cream to a simmer. Pour the cream over the chocolate pieces and let sit about 5 minutes.
2. Whisk the ganache until smooth and shiny. Set Aside. (Can stick it in the fridge to let it harden a thicken up a little. Don't use it while warm or it will melt the peanut butter filling.)

Peanut Butter Filling:
1. In a medium bowl, beat the cream cheese with the paddle attachment on medium-high until smooth and creamy. 
2. Lower mixer speed to medium and add the peanut butter, sugar, and vanilla. 
3. Gently fold the whipped cream into the cream cheese mixture until completely combined. Set aside.

Marshmallow Frosting:
1. In the bowl of a standing mixer, whisk the eggs and salt until fluffy and frothy.
2. Meanwhile, heat the sugar, corn syrup, water and vanilla paste. Heat over medium flame until the sugar is dissolved and just simmering, about 5 minutes.
3. With the mixer on medium speed, add a tiny bit of the hot sugar mixture to the egg whites at a time. (Temper the eggs - don't scramble the them)
4. Eventually, all of the sugar will be added and then turn the mixer up to high. Beat the mixture on high for about 5 minutes or until very stiff and shiny.

1. Place one chocolate cake and graham cracker cake round on your cake stand, with the graham cracker side facing up.
2. Spread half of your ganache on the graham cracker layer, followed by half of your peanut butter filling.
3. Place the second chocolate and graham cracker cake on top, with the graham cracker layer facing up. Repeat step two.
4. Place final cake layer, face down, on top of the peanut butter filling. Dollop the marshmallow frosting on top. I used the back of my spoon to swirl the frosting and create a textured look.
5. Carefully use a kitchen torch to brown some areas of the frosting.


  1. Trying this cake this weekend. It looks crazy good! Love to your mom. And thanks in advance for the 2 new found pounds ;). Kathy Hofer

  2. I totally agree about spreading out the baking, but somehow I always forget to do that!

  3. I'm going to come up with an excuse to make this in my near future...