This chocolate peanut butter cake recipe is insanely delicious. Two layers of rich, moist chocolate cake are frosted with a fluffy peanut butter meringue buttercream. If you’re serving a large crowd, you can instead make two single layer cakes to create more servings!
You guys, I know I have a lot of layer cake recipes on the blog, but this one might just be my new favorite. (Do I always say that? If so, I really mean it this time). After multiple tests and the seal of approval from my family and neighbors, I’m finally ready to share an absolutely incredible chocolate peanut butter cake.
If you love the flavor combination of chocolate and peanut butter as much as I do, make this cake! I promise you won’t be disappointed.
Chocolate Peanut Butter Cake Recipe Notes
- I kept the decorations very basic, but there’s room for creativity. You could top the cake with chocolate ganache (see my Banana Peanut Butter Layer Cake for a recipe and instructions on how to add it), or simply cover the top with chocolate peanut butter cups!
- Before placing the cakes in the oven, make sure the tops are level. This will help ensure that they bake evenly. If one side rises slightly more than the other, use a serrated bread knife to carefully even out the top.
- While not essential, I think certain tools like offset spatulas and parchment rounds are very helpful. If you’d like to know more about my cake equipment recommendations, as well as general tips and tricks, read How to Make a Perfect Layer Cake.
- Weight the flour on a kitchen scale if possible; it can make a huge difference! More here: How to Measure Flour.
- Make sure your baking powder is still active. Baking soda and powder expire over time, which will prevent cakes from rising.
- Don’t use natural peanut butter in the buttercream. Meringue buttercream is finicky enough as it is. You want to use a peanut butter brand that doesn’t separate, such as Jif or Skippy.
Can I Make Ingredient and Equipment Substitutions?
Avoid ingredient and equipment substitutions whenever possible, at least the first time you prepare a recipe. Different size eggs will change the structure of the batter. So will sugar with a different consistency (superfine sugar, raw sugar, etc). If you use non-dairy, skim or whole milk instead of half-and-half, the cake will be more dense and dry.
Increasing the size of the cake pan will increase the bake time and potentially impact the structure of the cake. For example, a 9-inch cake pan is actually 25% bigger than an 8-inch cake pan, so to get the exact same cake, you need to increase the ingredients by 25%. Learn more about this here.
Can I Use a Different Peanut Butter Frosting?
Meringue buttercreams are definitely more advanced than American buttercreams, but they’re worth learning how to make. The texture and flavor is infinitely better. However, I completely understand if you’re not ready to dive in. For a simplified peanut butter buttercream, try this recipe from Wilton.
When you’re ready to try the more advanced version, be sure to check out my Italian Meringue Buttercream post for tips and step-by-step photos (including how to fix it if it breaks).
What Is Half-And-Half?
This recipe calls for half-and-half. What is half-and-half, and how do you make it if you already have cream and milk in the fridge? Read my tutorial on how to make half-and-half so you can save time and money!
Natural Vs. Dutch-Process Cocoa Powder
This recipe uses Dutch-process cocoa powder. Did you know that different types of cocoa powder can produce different results in your recipe? If you’d like to know more about this, check out my post Natural vs. Dutch-Process Cocoa Powder.
Why Egg Size Matters in Baking
This recipe calls for large eggs. Using different size eggs can drastically impact baked goods. Don’t substitute a different size unless you have a kitchen scale to measure an equal weight by volume (ounces or grams) to get the same total amount of egg.
Read more about why egg size matters in baking (and how to make substitutions).
How to Measure Flour
For baked goods (as well as desserts like custard and ice cream), I always recommend using a kitchen scale to measure flour by weight instead of volume. Weight (ounces, grams, etc) will always give an accurate measurement of dry goods; volume (cups) can create varied results.
A cup of flour can weigh anywhere from 3 1/2 to 5 ounces. That could make a big difference in your recipe! If you still want to use cups, there’s a proper technique to make sure you get the best results possible.
My post How to Measure Flour explains all of this in more detail.
More Layer Cakes
Chocolate Peanut Butter Cake
- 7 ounces all-purpose flour (1 1/2 cups + 1 tablespoon using Spoon & Level Method)
- 2 ounces Dutch-processed cocoa powder (approximately 1/2 cup; I recommend Valrhona)
- 1 1/2 teaspoons baking powder
- 1 1/4 teaspoons kosher salt
- 6 ounces unsalted butter, room temperature
- 1 1/2 cups superfine sugar (11 1/2 ounces; see notes)
- 1 cup + 1 tablespoon half-and-half (or 50% whole milk + 50% heavy cream)
- 2 tablespoons brewed coffee or espresso, room temperature
- 1 tablespoon pure vanilla extract
- 4 large eggs, room temperature
Peanut Butter Buttercream
- 3 large egg whites
- 3/4 cup granulated sugar (5 1/4 ounces)
- 3 tablespoons water
- 8 ounces unsalted butter, cubed and at room temperature (preferably left out overnight)
- 1/8 teaspoon kosher salt
- 2 teaspoons pure vanilla extract
- 1/2 - 3/4 cup peanut butter, thinned out slightly in the microwave (make sure it’s not hot; slightly warm is fine)
Prepare the Cake:
- Set a rack in the middle of the oven and preheat to 350 degrees F. Very lightly grease the bottom of two 8-inch cake pans (do not grease the sides) and top with parchment rounds. Place the pans on a baking sheet, if possible (this will make taking both cakes in and out of the oven at once easier).
- In a medium bowl, thoroughly whisk together the flour, cocoa powder, baking powder and salt. In a liquid measuring cup, combine the half-and-half, coffee and vanilla. Crack the eggs into a small bowl or liquid measuring cup.
- In a stand mixer fitted with the paddle attachment, combine the butter and sugar on low speed for 3 minutes until pale and fluffy. If there are any bits of unincorporated sugar and/or butter on the sides or bottom of the bowl, use a spatula to incorporate them and mix for an additional 30 seconds.
- Add the eggs slowly, one at a time, stopping to scrape down the bowl all the way to the bottom after the second and final egg. The batter may begin to look slightly broken by the end of this step; it’s ok.
- On medium speed, swiftly alternate between adding the dry and wet ingredients, starting and ending with the dry. This shouldn’t take longer than a minute.
- Turn off the mixer and scrape down the bowl, all the way to the bottom, making sure there are no hidden dry patches. Turn the speed up to medium and beat for an additional 30 seconds to aerate the batter. Do not skip this step.
- Divide the cake batter evenly into the prepared pans. Use an offset spatula to even out the tops, ensuring the cake rises evenly.
- Bake for 28-30 minutes, or until a toothpick comes out clean from the center. Cool to room temperature before removing from the pan. Run an offset spatula or knife around the edges to help release the sides of the cake from the pan, then place a cardboard round or large cutting board against the cake pan and gently flip.
Prepare the Buttercream:
- Place the sugar and water in a medium-sized saucepan (do not stir). Cover and turn the heat to high. Once the liquid begins to simmer and steam develops, remove the cover (this helps prevent crystallization). Using a digital or candy thermometer, cook the sugar to the soft boil stage, 235-245 degrees F.
- While the sugar is cooking, whisk the eggs on high in a stand mixer fitted with the whisk attachment, until a soft peak has formed (for a more stable meringue, start the eggs on a lower speed and slowly turn the mixer up to high once the whites are frothy).
- Turn the mixer speed down to medium-low and very slowly pour the syrup down the side of the bowl into the egg whites (this will “cook” the egg whites, making them safe to consume. Don’t pour the hot syrup directly into the meringue or you’ll have scrambled egg whites.
- Once the syrup is completely incorporated, turn the speed to high. The meringue will continue to form a stiff peak as it cools down. Mix on high until the meringue comes to room temperature, approximately 15-20 minutes.
- Once at room temperature, slowly begin incorporating the soft butter on medium speed. Once all of the butter has been added, turn the mixer speed up to medium-high and slowly add the salt, vanilla, and peanut butter. Turn the speed back up to high at the end for about 30 seconds to fluffy up the buttercream.
Assemble the Cake:
- Place the first layer of cake on a revolving cake stand, removing the parchment paper. Placing a cardboard round below the cake is optional but will make transporting the cake easier after it is assembled.
- Spread approximately one cup of buttercream on the cake and spread it around evenly with an offset spatula. Add more buttercream as needed to reached the desired thickness.
- Place the second layer on top, evening it out with the first. Use an offset spatula to apply a thin layer of frosting to the side and top of the cake. Chill in the refrigerator for 30 minutes to set this first layer of buttercream. Cover the entire cake with a final layer of frosting. Grate some unsweetened or semi-sweet chocolate on top of the cake for decoration, if desired. (Ganache and/or chopped peanut butter cups would also be delicious on top).
- The finished cake can be stored at room temperature for up to 3 days; no need to refrigerate. After that it can go in the refrigerator for a few more days, but serve it at room temperature for best flavor and texture.
Please read my full post for additional recipe notes, tips, and serving suggestions!
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