The Baker Upstairs: The Best Chocolate Peanut Butter Cake


The Best Chocolate Peanut Butter Cake

This chocolate peanut butter cake is so luscious and decadent, with the perfect combination of flavors!

This chocolate peanut butter cake is so luscious and decadent, with the perfect combination of flavors!

Oh, man, I haven't been doing such a great job keeping up with this blogging thing lately, have I? I mentioned before that I recently got a new job, and it has thrown me for a bit of a loop as far as scheduling. I really do enjoy my job and I have learned so much in the six weeks I've been working there, but it has been a little tough to adjust to rotating days and nights, and no fixed work schedule. At my previous job, I had set days and hours and it made it easier to plan ahead for the blog. Now that I have a little more flexibility (and a little less certainty), I'm trying to find my balance again. I'm sure I'll get there eventually (hopefully!) but in the meantime, things may be a little more hit and miss around here. And thus, I am sharing my husband's birthday cake (from three weeks ago) on the blog today!

My husband Geoff is absolutely nuts about peanut butter and chocolate together, and this is one of his very favorite cakes. In the past I've made it as cupcakes, and they've been tasty, but there's something so fun (and elegant) about a layered cake. I think the layered cakes are especially fun to decorate! Though my decorating skills are still far from perfect, I can see improvement with each cake I decorate. I definitely think the roses on this cake are the best I've done so far... I think it helped that the frosting was a little on the stiff side, so the roses held their shape really well. I also love that my husband is a thirty four year old man who doesn't mind when his wife pipes roses all over his cake. :)

This chocolate peanut butter cake is so luscious and decadent, with the perfect combination of flavors!

This cake is definitely a little on the rich side, so I was fine with a small slice, but Geoff devoured a giant slice with a big glass of milk on the side. If you love peanut butter and chocolate like he does, this is definitely the cake for you!

The Best Chocolate Peanut Butter Cake

for the cake:
1 1/2 cups sugar
1 cup flour
1/2 cup cake flour
1 cup unsweetened cocoa powder
1 1/2 teaspoons baking powder
1 teaspoon baking soda
1/2 teaspoon salt
8 ounces (1 cup) cold butter, cut into pieces
4 eggs
1 cup sour cream
2 teaspoons vanilla

for the frosting:
1/2 cup butter, softened
2/3 cup peanut butter
3-4 cups of powdered sugar
1 teaspoon vanilla extract
1-2 tablespoons of milk
pinch of salt
5-6 chopped Reese’s peanut butter cups

Preheat the oven to 350. Grease and flour two eight inch round cake pans. In a large bowl or the bowl of a stand mixer, whisk together the sugar, flour, cake flour, cocoa powder, baking powder, baking soda, and salt. Add the butter and mix until the mixture resembles coarse crumbs. Add the eggs one at a time, mixing well after each addition. Add the sour cream and vanilla, and mix well. Divide the mixture evenly between the two prepared cake pans. Bake 30-35 minutes, or until the tops spring back when touched and a toothpick inserted in the center comes out clean. Remove and let cool completely.

To make the frosting, beat the butter and peanut butter together until light and fluffy. Add the powdered sugar, vanilla, milk, and salt, adjusting the milk and/or powdered sugar as needed to form a smooth frosting. Beat until light and fluffy and frost cake as desired. Top with chopped Reese’s peanut butter cups.

cake adapted from Baking a Moment and frosting adapted from How Sweet It Is

This chocolate peanut butter cake is so luscious and decadent, with the perfect combination of flavors!


  1. when you said 1 cup flour and
    1/2 cup cake flour what is the different? can you please give names of the flour you used.

    1. The 1 cup of flour is all purpose flour. Cake flour is different than all purpose flour and has less protein. I used Softasilk brand. I found it at the grocery store. If you can't find it, this article has instructions for making cake flour at home:

    2. Thank you, cake flour is not available in Australia! I substituted 2 tbsp cornflour in 1 cup plain flour.

  2. I made this one in my food processor and it worked very well. Everyone loved it! I used a different peanut based chocolate bar as I couldn't get the one's you used. Thanks for the recipe!

  3. Do you use salted or unsalted butter?

    1. I always use salted butter. It's a personal preference.

  4. Looks beautiful! How did you pipe the roses?

  5. I think even a novice baker such as myself could follow the easy directions provided by Big Sis. piping tips

  6. Does this cake need to be refrigerated?