Dark Chocolate Layer Cake with Peanut Butter Frosting

An easy two-layer dark chocolate cake covered in creamy, dreamy peanut butter frosting, all from scratch!

While Valentine’s Day may already be behind us, I think the whole month of February, or at least the remainder of this week, deserves to pump out some extra love, don’t you agree?

And since we’re already into the second month of 2017, I owe you another Cake of The Month.

All that said, I thought it would be incredibly appropriate to bring you a chocolate peanut butter number because I’m pretty sure it’s been scientifically proven by tastebuds around the world that chocolate + peanut butter is the ultimate flavor combo and if flavors were people, this couple would be the “it” one and super in love.

So… Post-Valentine’s Day Cake of The Month, comin’ atcha nice and sweet.

I’ve been having a lot of fun planning out this year’s cake recipes, and while I do have a chocolate layer cake on the blog already, this dark chocolate layer cake is a little different from that, though very similar.

I want to show you how not every chocolate cake is created equal (just like not every chocolate chip cookie is either), and how changing up just a few things in your ingredient list can yield not only a different flavor, but also a different texture and density.

To change things up for this dark chocolate cake while using my classic chocolate cake recipe as a guide, I wanted to create a deeper, darker, less sweet flavor without sacrificing any moisture. So I opted for half granulated and half brown sugar rather than straight up granulated.

The result is a super moist chocolate cake, with deep chocolate flavor. 

This sugar blend brings some extra moisture to the crumb while also giving the dark chocolate of the Dutch processed cocoa powder (rather than unsweetened cocoa powder) some deeper molassesy notes.

I also completely cut out the buttermilk and opted for doubling the amount of eggs to 4. More eggs = denser texture = heavier, sturdier cake to complement the dark chocolate essence I was aiming for.

Now. The most important player here in this cake game: peanut butter buttercream. BELIEVE ME when I tell you that this frosting is a little gift from the cake gods.

It is absolutely irresistible, and I can tell you from experience that you may find yourself with several dirty spoons and way less frosting than you thought you had once you have one lick of this stuff.

To say it’s incredible is somehow an understatement. And the best part? It’s so freaking simple.

Butter, creamy peanut butter, powdered sugar, a touch of vanilla, and some milk/cream/water. I’ve been making this peanut butter frosting for years and it never disappoints. Try it on pretzels, graham crackers, a yellow cake, brownies…

Truly anything that pairs well with peanut butter can use some peanut butter buttercream on top. No judgment if it never sees anything other than your dark chocolate cake and a spoon, though.

This cake was a request by my manager at work for her birthday, and it certainly did not disappoint. I shared this cake with several coworkers over the course of a couple days, and there may or may not have been elbow shoves over the last few slivers.

Of course, no dark chocolate cake with peanut butter frosting is complete without a generous sprinkle of chopped peanut butter cups, so while you’re at it, toss some into the smear of frosting between the two cake layers.

Deep, dark, moist chocolate cake paired with a sweet and creamy peanut butter frosting is just what your Friday needs. I’m thinking this is the perfect way to round out Valentine’s Day week, and adding this cake to your baking arsenal is the best way to spread some love all around!

Print Recipe

5 from 2 votes

Dark Chocolate Layer Cake with Peanut Butter Frosting

An easy two-layer dark chocolate cake covered in creamy, dreamy peanut butter frosting, all from scratch!

Prep Time10 mins

Cook Time30 mins

Total Time40 mins

Servings: 12 servings

Ingredients

DARK CHOCOLATE CAKE

• 1 cup granulated sugar
• 1 cup packed light brown sugar
• 2 cups all-purpose flour
• 3/4 cup Dutch processed cocoa powder
• 2 teaspoons baking powder
• 1/2 teaspoon baking soda
• 1 teaspoon salt
• 4 large eggs
• 1/2 cup vegetable oil
• 2 teaspoons vanilla extract
• 1 cup coffee + water to 1 and 1/4 cup liquid*

PEANUT BUTTER FROSTING

• 1 and 1/2 cups creamy peanut butter
• 1/2 cup (1 stick) unsalted butter softened to room temperature
• 3 cups powdered sugar
• 1 teaspoon vanilla extract
• 1/3 to 1/2 cup milk, cream, or water

Instructions

DARK CHOCOLATE CAKE

• Preheat the oven to 350ºF. Grease and flour (or use homemade cake release) two 8-inch round cake pans. Set aside.
• In a large bowl, whisk together the granulated sugar, brown sugar, flour, cocoa powder, baking powder, baking soda, and salt. Set aside.
• In a small bowl, whisk together the eggs, vegetable oil, and vanilla extract until completely combined. Pour the wet ingredients into the dry ingredients, add the coffee, and whisk or stir the batter until everything is combined.
• Divide the batter evenly between the prepared pans. Bake for 28-30 minutes, or until a toothpick inserted into the center of the cake comes out mostly clean. Remove from the oven and allow to cool completely on a wire cooling rack before assembling.

PEANUT BUTTER FROSTING

• In a medium size bowl with a handheld mixer or in the bowl of stand mixer fitted with the paddle attachment, beat butter and peanut butter on medium speed until smooth (about 3 minutes).
• Decrease mixer speed to low. Add powdered sugar, vanilla extract, and milk/cream/water. Increase mixer speed to to high and beat until completely combined (approximately 2-3 minutes). If frosting is too thick, add more liquid to desired consistency.

ASSEMBLE THE CAKE

• Trim cooled cake layers to create a flat surface. You can do this with a large serrated knife or a cake leveler. Place one layer on a plate or cake stand and cover the top with peanut butter frosting frosting. Spread evenly with an offset spatula. Sprinkle with chopped peanut butter cups, if desired.
• Place second layer on top, cut surface down. For a sturdier cake, refrigerate at this point for about 10 minutes. When cake is slightly chilled, remove from refrigerator and spread more frosting on the top and around the sides. Decorate with more chopped peanut butter cups, if desired. Serve. Leftovers stay fresh, covered tightly, at room temperature up to 5 days and in the refrigerator up to 1 week.
• Make ahead: prepare cakes and frosting up to 1 day in advance. Cover cakes tightly and keep at room temperature or in the refrigerator until ready to assemble. Refrigerate prepared frosting in an airtight container until ready to use. Unfrosted cake layers may be frozen, wrapped tightly, up to 2 months. Thaw overnight in the refrigerator before assembling. Frosted cake can be frozen, wrapped tightly, up to 2 months. Thaw overnight in the refrigerator and bring to room temperature before serving.

Notes

*This means brew a cup of coffee then add water until the level reaches 1 and 1/4 cup total.

Adapted from King Arthur