Peanut Butter Cup Cake

Today, I turn 34 years young, and I have the most serious of serious questions to ask. Does this mean I’m now in my mid-30’s? If the answer is yes, don’t tell me. It dumbfounds me to think that at 34 years old, my mom already had a 9-year-old and a 7-year-old. I barely feel like a grown-up, save for the mortgage payments and general responsibilities that come with not being 18 anymore.
If time is going to keep on moving, we might as well welcome it with open arms and some phenomenal cake, right? I have had this cake on the brain for months, but decided to shelve it and save it for my birthday. I couldn’t think of anything more perfect for me than an overdose of chocolate and peanut butter to the highest degree.

I basically took my favorite chocolate cake, my favorite peanut butter frosting, tons of peanut butter cups, and smooshed it all together into one of the most fabulous cakes I have made to date.
For someone who could eat chocolate and peanut butter for breakfast, lunch and dinner, this cake is a dream come true.

The cake is the same one I used for my Snickers cake last year; do you remember how much I went on and on about how it’s the best chocolate cake ever?
Well, it’s still the best chocolate cake ever.
Case closed.
Save This Recipe

The peanut butter frosting is a double batch from my chocolate-peanut butter cupcakes, and I love it because it’s silky smooth, super peanut butter-y and not at all too sugar-y. I would love to just eat it from a bowl with a spoon. However, I’ll settle for it on this cake along with tons of chopped peanut butter cups, because, of course, there needs to be peanut butter cups.

I plan to spend my birthday relaxing, going to a hockey game, and eating a ridiculous amount of dessert.
That’s what birthdays are for, right?

One year ago: Italian Easter Pie
Three years ago: Tiramisu Cupcakes
Four years ago: Easy Vanilla Bean Buttercream
Six years ago: Slow Cooker Beef Burgundy
Watch How to Make the Peanut Butter Cup Cake:

Peanut Butter Cup Overload Cake
Ingredients
For the Cake:
- 2½ cups (312.5 g) + 1 tablespoon all-purpose flour
- 3 cups (600 g) granulated sugar
- 1 cup (86 g) + 1 tablespoon Dutch-process cocoa powder
- 1 tablespoon baking soda
- 1½ teaspoons (1.5 teaspoons) baking powder
- 1½ teaspoons (1.5 teaspoons) salt
- 3 eggs, at room temperature
- 1½ cups (360 ml) buttermilk, at room temperature
- 1½ cups (355.5 ml) strong black coffee, hot
- ¾ cup (163.5 ml) vegetable oil
- 4½ teaspoons (4.5 teaspoons) vanilla extract
For the Peanut Butter Frosting:
- 2 cups (240 g) powdered sugar
- 2 cups (516 g) creamy peanut butter
- 10 tablespoons unsalted butter, at room temperature
- 1½ teaspoons (1.5 teaspoons) vanilla extract
- ½ teaspoon (0.5 teaspoon) kosher salt
- ⅔ cup (158.67 ml) heavy cream
For the Chocolate Ganache:
- 8 ounces (226.8 g) semisweet chocolate, finely chopped
- ¾ cup (178.5 ml) heavy cream
- 30 miniature peanut butter cups, coarsely chopped, divided
Instructions
- Make the Cake: Preheat oven to 350 degrees F. Grease three 8-inch round cake pans, line the bottoms with rounds of parchment paper, grease the parchment, then flour the insides of the pans, tapping out excess; set aside.
- In the bowl of an electric mixer (or large mixing bowl if you’re using a hand mixer), sift together the flour, sugar, cocoa powder, baking soda, baking powder and salt. In a medium bowl, whisk together the eggs, buttermilk, coffee, oil and vanilla.
- Add the wet ingredients to the dry ingredients and mix for 2 minutes on medium speed. Scrape the sides and bottom of the bowl and mix for an additional 20 seconds (the batter will be very thin).
- Divide the batter evenly among prepared pans. Bake for 20 minutes and rotate the pans in the oven. Continue to bake until a toothpick inserted into the center of one of the cakes comes out almost clean (with a few moist crumbs), about 12 more minutes. Cool the cakes (in the pans) on wire racks for 20 minutes, then carefully turn them out onto cooling racks to cool completely.
- Make the Peanut Butter Frosting: Place the powdered sugar, peanut butter, butter, vanilla and salt in the bowl of an electric mixer fitted with a paddle attachment. Mix on medium-low speed until creamy, scraping down the bowl with a rubber spatula as needed. Add the heavy cream and beat on high speed until the mixture is light and smooth (do not overbeat).
- Assemble the Cake: If your cakes baked up uneven or have domed on top, level off the tops. Place one cake layer on a serving plate. Cover with 1 cup of the peanut butter frosting and sprinkle 10 of the chopped peanut butter cups over the frosting. Top with a second cake layer and cover with another 1 cup of the peanut butter frosting, and top with another 10 chopped peanut butter cups. Place the final cake layer on top face-down. Frost the cake with the remaining peanut butter frosting, finishing it as smoothly as possible. Refrigerate the cake for at least 1 hour, until the frosting is set.
- Make the Chocolate Ganache: While the cake chills, make the chocolate ganache. Place the chocolate in a 4-cup measuring cup; set aside. Place the cream in a small saucepan over medium heat and warm until it just comes to a boil. Pour the cream over the chopped chocolate and let sit for 2 minutes. Begin whisking the mixture in the center, gradually working your way outward until the ganache is completely smooth. Set aside to cool, whisking occasionally, until it has thickened slightly, yet still a pourable consistency.
- Garnish the Cake: If the ganache was mixed in a bowl, transfer it to a 2-cup measuring cup. Slowly pour the chocolate ganache into the center of the cake, letting it push itself outward and flow over the sides of the cake. Top with the remaining 10 chopped peanut butter cups. Refrigerate the cake for at least 30 minutes, giving the ganache a chance to set up. Keep the cake refrigerated, removing it from the refrigerator about 20 minutes prior to serving.
Notes
Did you make this recipe?
Leave a review below, then snap a picture and tag @thebrowneyedbaker on Instagram so I can see it!



Happy Birthday!!!!! This cake looks RICULOUSLY AMAZING!!!!!!!!
I am 34 years old as well… I will be 35 in September… I think the exact same way as you….. My parents had a 15 and a 10 year old at 34…. I have 3 dogs and a mortgage. LOL!!!!
Hope you have a great day! Go Pens!
Happy Birthday! Beautiful cake. Enjoy your day and dessert and ‘Lets Go Pens!’
Happy Birthday! I really enjoy your recipes. I can almost taste that birthday cake, pictures are awesome
Happy Birthday!!!!! Your cake is the perfect way to celebrate your birthday! I would LOVE one of these cakes for my b-day! It looks just amazing!!!!!!!!!! Enjoy your day!!!
Happy Birthday!!! Awesome cake. I’m saving it for my daughter’s birthday – she’s 21 one this year and adores peanutbutter and chocolate. Can’t wait to surprise her in July!
Happiest Birthday to YOU!! Have the best day! With this cake, how can you not?! It just shot to the top of the list for my birthday cake in July.
Happy Birthday! Enjoy your cake!
Happy Birthday Michelle, this cake looks epic!!! Have a fabulous day :)
HAPPY BIRTHDAY – Everything of the best and don’t worry about your age. You really don’t look it :) Thanks for the recipe. It looks amazing! Hope you had tons of birthday cake x
Beautiful cake! Looks delicious and it should help enhance your very special day. Happy Birthday!
Happy Birthday today, and that is a very delicious looking cake you have!
Happy, Happy Birthday, Michelle. I am well past your age but 34 was one of those years that I would like to go back to…just a really good, peaceful, happy time in my life. Actually, I really loved all of my 30’s. Enjoy this day and that super delicious cake.
Happy Birthday Michelle!!!I think you have made the Best Cake ever!!!Enjoy!!!!
Happy Birthday!!!! This cake looks fabulous !!!I I want it for my birthday!!!
Happy Birthday! You are still in the first quarter of your life and 34 is just a number. Eat cake! Especially if it is this one! Enjoy your day!
Happy Birthday!! What a fabulous cake you have to celebrate the occasion. That ganache looks to die for – you had me at the lead photograph. Looks so beautiful. Wishing you a wonderful day!
HAPPY BIRTHDAY MICHELLE!!!! Who cares about age when you you have an AMAZING cake to celebrate with :-)
Well the snickers cake is a fave around here and amazing …I can’t imagine anything being better…until this…hehe…guess I need to go to the kitchen and find out! :) Thanks for sharing this!!!
Happy Birthday! You and I share a birthday, and, like you, I generally make something for it since I’m the baker in the family, so for the past several years, I’ve looked forward to seeing the wonderful birthday desserts you’re going to post because they always seem to be exactly what I want. This is no exception. I was craving a chocolate peanut butter cake. I usually am. I made the birthday chocolate PB cheesecake one year and it was too good for words. This also looks amazing, and I’m so excited to make it!!
Hope you have a great birthday today!!! Thanks for the perfect birthday dessert, as always!
Happy Birthday, Jessica!! Have an awesome day!
Awesome cake, birthday girl! I love that you chopped the regular-sized Reese’s (more peanut butter per bite than the mini-sized ones) to put on the cake. I also love that this is peanut butter and chocolate overload madness. We happen to be the same age and like you, I could eat chocolate and peanut butter all day. This cake is on reserve for my next birthday!
Ong I love Peanut Butter Cake. Happy Birthday
Happy Birthday!!! And what a gorgeous cake! Glad that you stuck with your fave choc cake base and then went nuts with all that PB! YES!! My kind of birthday cake! Pinned to multiple peanut butter boards!
Happy Birthday, Michelle!
this cake looks amazing – perfect birthday cake for you!
You are such an inspiration to so many of us, thanks for sharing your life with us!
I wish you a great day with everything and everyone you love!
Hugs from Switzerland,
Gry
This is one of the best cakes I have ever made! I made it for my husband’s birthday and it was a big hit. If you love chocolate and peanut butter you have to try this recipe!!
Happy Birthday and what a SMASHING cake!! Your def still only early thirties so don’t stress! :)
Happy Birthday, Michelle! In my book, you’re still considered as in your early thirties. Next year, I can’t help ya. ;) This cake is phenomenal! Wouldn’t our 10-year-old selves flip out over it? Thanks for sharing and enjoy your birthday week!
Happy Birthday! Don’t be in a rush to be in your mid-thirties, your still in the “rounding down” bracket til next year. This cake is total BONKERS!! I have a 13 year old young man in my house that would love me forever if I made something like this. = )
Happy Birthday, Michelle! What an incredible cake – I love the PB cups sandwiched between each layer and the ganache makes it a bit like a giant PB cup!
Happy Birthday…this cake looks awesome!!!! My husbands birthday is next month and he loves Chocolate and Peanut Butter…I have to make this cake for him.
Happy Birthday, Michelle!! No, you are not in your mid-thirties! (Next year might be another story.) Have a wonderful day and enjoy your cake; It’s divine! :)
Firstly, Happy Birthday! I married my husband at 34 so you’re ahead of me!
Secondly, this is my DREAM cake! My birthday isn’t until December, but I’m planning on celebrating early with this!