Biscoff S'mores Cake

5 from 3 votes

Chocolate Biscoff cake baked on Biscoff cookie crust, filled with toasted marshmallow fillings, chocolate ganache, and Biscoff buttercream.

Course: Dessert

Cuisine: Cake

Keyword: biscoff, biscoff buttercream, Biscoff S'mores Cake, s'mores

Preheat your oven to 375 degrees F. Spray three 8-inch round cake pans with non-stick spray and then line with parchment. Spray again. Set aside.
In a medium sized bowl combine the Biscoff cookie crumbs, melted butter and sugar. Stir until all the crumbs are damped by the melted butter.
Divide evenly between the three pans (4 ounces in each) and press down firmly with your hand or the back of a measuring cup.
Bake for 5 minutes, until golden brown. Let cool while you make the cake batter.

Preheat your oven to 325 degrees F.
In a medium-size bowl, combine the Biscoff crumbs, all-purpose flour, cocoa powder, baking powder, baking soda, and salt. Whisk until the ingredients are well-blended. Set aside.
In the bowl of a stand mixer fitted the paddle attachment, beat the butter, granulated sugar and brown sugar on medium speed until light and fluffy, about 2 to 3 minutes.
Add the eggs, one at a time, beating well after each addition, making sure to scrape down the bowl between additions. Continue to beat the mixture for a few more minutes, until the mixture is smooth. It’s not done until it looks cohesive, meaning, it should not look curdled. We want it to be smooth.
With the mixer on low speed, add 1/3 of the dry ingredients and mix until combined. Slowly add half of the buttermilk and mix until incorporated. Continue alternating the flour mixture and buttermilk until it has all been incorporated. Scrape down the sides of the bowl and slowly mix for another 20-30 seconds.
Pour the batter onto the Biscoff crust in each pan (about 18 ounces in each) and bake for 30 to 35 minutes, or until a toothpick inserted in the center of the cake comes out with a few moist crumbs on it. Cool 10 minutes on a wire rack before inverting onto a cooling rack to cool completely.

Place the marshmallows on a cookie sheet lined with parchment paper and sprayed with nonstick cooking spray. Place on the middle rack of the oven, and broil the marshmallows until golden brown on top, about 30-60 seconds. Keep your eye on them!
Remove the pan from the oven and gently turn the marshmallows over and broil them again until they are golden brown on the other side.
In the bowl of a stand mixer fitted with the paddle attachment, combine the butter and powdered sugar and beat on low until blended. Add the vanilla and mix on medium speed for about three minutes
With the mixer on low speed, add the marshmallow cream and (slightly cooled) toasted marshmallows, and mix for about one minute.

In a microwave safe bowl, pour the cream over the chocolate chips and heat for about 45-60 seconds. Stir, and if needed, heat for another 30 seconds to melt the chocolate chips completely. Let cool to room temperature before using.

In the bowl of electric mixer fitted with the paddle attachment, combine the butter and Biscoff spread. Beat on medium-high speed until smooth, about 45 seconds.
Add the powdered sugar to the bowl and mix in, slowly at first until incorporated, then increasing the mixer speed to high. Blend in the vanilla extract, salt and heavy whipping cream, and continue to whip on high speed until very fluffy, about 4-5 minutes, scraping down the sides of the bowl as needed.
Beat frosting by hand with a wooden spoon to get air bubbles out.

Place the first cake layer, graham cracker side down, on a cake board.
Pipe a rim of buttercream around the edge of the cake and then spread about half of the marshmallow filling evenly across the cake. Drizzle with chocolate ganache.
Place the second cake layer, graham cracker side down, on top and follow the steps above.
The final cake layer should also be placed graham cracker side down. Cover the cake with a thin layer of buttercream around the entire cake. Freeze for 15 minutes.
Finish frosting the cake with the remaining buttercream.