soft and moist dark chocolate cake with a creamy and nutty peanut butter frosting, topped with a dark chocolate ganache. Made in a 9x13 for easu crowd serving!
For the chocolate cake
Course Dessert
Cuisine Cake
Keyword sheet cake, peanut butter, ganache
Servings 16Squares
Author Molly Murphy
Ingredients
For the chocolate cake
3eggs room temperature
1cupbuttermilk room temperature
1cuphot water
½cupvegetable oil
2cupsall-purpose flour
1 ¾cupsgranulated sugar
¾cupspecial dark cocoa powder
2teaspoonsbaking soda
2teaspoonbaking powder
1teaspoonsalt
1tablespoonpure vanilla extract
For the peanut butter buttercream
1cupunsalted butter room temperature
¾cupcreamy peanut butter I use Skippy
5cupspowdered sugar
2teaspoonspure vanilla extract
¼cupheavy whipping cream
¼teaspoonof salt
For the chocolate ganache:
1cupsemisweet chocolate chips or chopped chocolate
Preheat your oven to 350 degrees. Spray a 9×13 metal pan on the bottom, line with parchment paper, and spray again. If you need to use metal binder clips to hold down the sides, remember to use metal, not plastic. Set aside
In a large bowl, sift the flour, sugar, cocoa powder, baking soda, baking powder, and salt. Mix on low until evenly combined. Set aside.
In another small bowl, whisk the eggs, buttermilk, hot water, vanilla extract, and vegetable oil until evenly combined.
Slowly pour the liquid ingredients into the dry ingredients and using a whisk, gently mix just until combined. There should be no flour streaks. With a rubber spatula, scrape the bottom of the bowl to make sure the batter is evenly combined.
Evenly distribute the cake batter to the prepped cake pan. With the back of a spoon, even out the batter to ensure it’s smooth for baking.
Bake for 35-40 minutes. Check the cake by inserting a toothpick. It’s done when it comes out with just a few moist crumbs on it.
Let it completely cool in the cake pan. While the cake cools, make the peanut buttercream.
For the peanut butter buttercream
In the bowl of electric mixer fitted with the paddle attachment, combine the butter and peanut butter. Beat on medium-high speed until smooth, about 2 minutes.
With the mixer on the lowest speed, add the powdered sugar, vanilla, salt, and cream to the bowl. Once mixed, beat on medium speed for 3 minutes, scrape down the bowl.
Optional: Use a wooden spoon to mix frosting one last time to get rid of air bubbles.
Chocolate ganache
When the cake is ready for assembly start by making the chocolate ganache. Place the cream in a medium microwave-safe bowl, and heat until the cream is hot and slightly bubbly, so it will melt the chocolate. I always start with 30 seconds and check it. It might take longer, it just depends on your microwave. Remove from the microwave, and add the chocolate, let the mixture sit for 5 minutes without touching it. Once ready, stir until everything melts and the mixture is smooth.
Assembly
Once the cake has completely cooled in the pan, use an offset spatula to spread a generous layer of peanut butter buttercream evenly over the top of the cake. Make sure to cover the entire surface. Place the cake in the fridge or freezer for 5-10 minutes.
If you haven’t already, prepare the chocolate ganache by heating the cream until hot and slightly bubbly, then adding the chocolate. Let it sit for 5 minutes, then stir until smooth.
Pour the chocolate ganache over the top of the slightly chilled peanut butter buttercream, spreading it evenly with a spatula to cover the entire surface. Allow the ganache to set slightly, about 5 minutes.
Once the ganache has set a bit but is still slightly tacky, using a wilton 8B piping tip, pipe a border around the edge of the cake using the remaining peanut butter buttercream.
Optionally, garnish the cake with chopped peanuts or Reeces peanut butter cups.
Allow the cake to set completely before slicing and serving.
Slice the peanut butter sheet cake into squares or rectangles, and enjoy!