Chocolate Peanut Butter Cake

Layers of moist, rich chocolate cake. Cream cheese in the peanut butter frosting to cut through some of the richness. A peanut butter fudge ganache.

I first made this Chocolate Peanut Butter Cake for Alex's birthday 7 years ago. We had a party, fed it to a ton of people, and still had way too much left over. But it was incredibly delicious.

Since it was so good, so decadent, I decided to bring it out again this year. 2020 is different than 2013, of course. I'm just feeding 3 of us; no need for a cake that feeds 20.

So this year I halved the recipe and converted the cake from 3 layers to 2 layers. So much more manageable!

Some people love peanut butter. I am not usually one of those people. I usually choose a good, pure vanilla, dark chocolate, lemon, or berry. But this cake, man. It is fantastic. I'm not going to wait another 7 years to make it, and I hope you don't, either.

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How to Make the Cake

I feel sorry for Alex when we share a dessert because peanut butter-chocolate is not, and will not ever be, one of my top 3 dessert choices. When it's this cake, though, it might be dessert choice #4.

Although it looks impressive, this cake is rather easy to make. I made the cake batter with only a large bowl and a whisk. Frosting is an easy decorator's buttercream with cream cheese - no cooking required. And ganache only involves melting and stirring. Assembly, likewise, was simple.

When I made this cake 7 years ago, I made a large, 3-layer cake, exactly as Smitten Kitchen had adapted it from Sky High: Irresistable Triple-Layer Cakes. This time around, for just 3 of us, I decided to halve the recipe to convert the dessert into a more reasonable 2-layer cake.

Start off by greasing and flouring two 8-inch or 9-inch cake pans. With a chocolate cake, use cocoa powder instead of flour if possible. Just tap it around the pans, and then you can dump the extra flour or cocoa into your mixing bowl.

Cake batter is super easy. Just mix together your dry ingredients in a large bowl. Use a whisk to add the oil, yogurt, and egg. Oil keeps the cake more moist than butter does; adding these three before the water helps you blend them in completely (so you don't have chunks of egg white in your cake, etc.).

Next, whisk in the water, vinegar, and vanilla. Stir until just combined, then divide between your prepared cake pans and bake. I always stick a toothpick into the center of my cakes; if it comes out clean, your cake is done. Cool your cakes completely before making frosting.

Sometime between getting the cakes into the oven and taking them out, pull out the cream cheese and butter to soften for the frosting. Cream cheese in particular can be lumpy if you try to blend it while it's still cold.

When you're ready to frost the cake, pop the 2 cake layers into the freezer while you make the frosting. Then, just blend together the cream cheese and butter with a hand mixer (affiliate link). Add the powdered sugar, and mix a lot more. Then mix in the peanut butter.

This is just the perfect amount of frosting for me, but frosting lovers may disagree. To make it with a little more frosting, increase the quantities by 50%.

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Cake Assembly and Ganache

Take a cake layer from the freezer, and turn it out onto your cake plate. I do this by placing the cake plate directly on the cake pan, and flipping it. I had no problems removing this cake from the pans. If it doesn't come out, try tapping the bottom of the cake pan; the layer may fall out that way. Next, try loosening up the sides; if you have a flexible cake spatula, you can try to get it underneath the edges of the cake.

To keep your cake plate clean, cut strips of wax paper and place them between the edges of your cake and the plate. Any rogue frosting gets on the waxed paper, which you will just pull out and throw away, and your cake will look prettier later.

Spread a small amount of frosting over the layer, almost to the edge. You don't want it too far out; the top layer will squish the frosting down a little to the edge.

Turn out your second cake layer onto a second plate, then place it on your bottom layer.

You've two options for frosting here - making a crumb coat, or just frosting the whole thing. To make a crumb coat of frosting, use just barely as much frosting as necessary to coat the whole cake. Chocolate cake crumbs will get in the frosting. Freeze the cake for 15-30 minutes to allow the frosting to set, then use the remaining frosting (and a fresh knife) to hide this speckled coat.

We'll top this with chocolate ganache, so I don't worry about a crumb coat very much. Regardless, once you've placed the second layer of cake, start frosting the top of the cake, pushing extra frosting down the sides of the cake. Then frost the sides all the way down to the waxed paper.

You can stop here with your cake-making, but the ganache is really fantastic, so I don't know why you would.

Chill your cake while you make the chocolate ganache. Don't use a very dark chocolate here. You want semisweet, maybe around 50-60% chocolate. It's a rich enough cake that a really dark chocolate will be too much.

Combine the chocolate, peanut butter, corn syrup, and half and half in a saucepan. Melt the chocolate with everything else under low heat. Stir until smooth (although honestly, mine wasn't very smooth). Immediately pour over the chilled cake; the ganache won't pour easily if you let it cool.

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Serving and Storing the Cake

Since this cake has cream cheese in the frosting, you should store it, covered, in the fridge. While it's on the cake plate, I usually just press plastic wrap against the sides. Once we have less than half the cake left, I cut it into slices and put it in containers for storage.

The cake itself is incredibly rich and moist. The peanut butter frosting is sweet and peanutty, but the cream cheese tempers it so that it's not tooth-achingly sweet. The ganache gilds the cake. Each component is delicious on its own - I kept sneaking bites while I made this - but they're amazing together.

I would say this cake easily serves 12. I love this amount of cake because it's not overwhelming. Alex and I (and Amelia, when I let her) ate it in just a few days, but it's such a moist cake that it will be good for 4-7 days, wrapped well and stored in the fridge.

This is a very pretty and presentable cake, one that seems much more difficult to make than it actually was. A great use of a few hours in the kitchen! It will delight any peanut butter lover in your life. I can't recommend it highly enough.

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Have you tried this recipe? Or have a question about it? Rate it or leave a comment below! (PS: rating my recipes helps other people find them, too!)

Want other chocolate peanut butter sweets? Try Chocolate Peanut Butter Cheesecake, and these healthy Chocolate Peanut Butter Bites.

In the past:

Three Years Ago: Salmon with Baked Couscous (still a favorite!); Slow Cooker Baked Beans

Four Years Ago: One-Pan Farro with Tomatoes

Six Years Ago: Oatmeal Sandwich Bread; Chocolate Chip Cookie-filled Pretzels

Seven Years Ago: Fresh Blueberry Pie

Ten Years Ago: Chocolate Chip Oatmeal Cookies

📖 Recipe

[Originally posted June 24, 2013. Text, photos, and recipe updated August 2020.]