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!



This chocolate cake really is the best chocolate cake ever. It is the only one I make.
LOL! As soon as I saw the picture, I knew exactly why you made this. Happy, happy birthday!
Happy Birthday; the best is yet to come!
Woahhh that cake is a masterpiece. Happy birthday! You spent the day exactly as you should – relaxing, eating, and doing what you love. Keep doing you!
Happy Birthday! Keep all the great recipes coming & enjoy your birthday! It’s just a number; you’re only as old as you feel!
Happy Birthday!
Happy Birthday Michelle! Hope you have a great day with your pups and CCC :)
That cake looks absolutely amazing, is it available for order?!
Hi Katie, Thank you! I do not do any baking orders, I’m sorry!
HAPPY BIRTHDAY!!! Hope you have a fantastic day and many blessings in the year ahead!
I can’t wait to try this. After I read the recipe & finished drooling, I saw this article about “9 Amazing Cakes To Make For Birthdays” and was sooooo excited to see you on there. Congratlations!!!
http://www.philly.com/philly/food/20140325_Parade_9_Amazing_Cakes_to_Make_for_Birthdays.html
Happy birthday! :) You’re in your low 30’s for one more year, so live it up! haha With this cake, you’re doing just that. Enjoy your hockey game and your day. And you’re still much younger than me. :)
Happy birthday to you.. happy birthday to you..
happy birthday happy birthday
happy birthday to YOU!
The cake looks like heaven! can’t wait to try it! Have a nice birthday :)
Michelle, happy birthday! Enjoy and remember age is just a number. Great looking cake…..I want piece!
Happy Birthday you young pretty “Girl” Enjoy your youth and just revel in it. Age is only a number. It is how you feel inside that reveals your true age. I turned 60 this year and still feel like a 16 year old girl. Never stop laughing, having fun and being a free spirit. As for this incredible cake…out of this world and I can’t wait to try it. Peanut butter and chocolate are heaven on earth!
That is a dream of a cake! I can’t imagine anything more fantastic.
May your day be everything you wish for and more! Happy birthday, Michelle!
Happy Birthday!! I can’t think of a better birthday cake to celebrate with! This looks delicious; I will definitely be trying this!
Happy Birthday Michelle!!
My birthday is in 3 days and, as the baker of the family, I think you’ve given me the PERFECT cake to bake! I’m totally crazy about peanut butter & chocolate. Hope your 34th is wonderful! :)
I cannot believe we have the same birthday. Michelle, happy birthday. I pray for good health and blessings to you. And more delectable desserts to come.
Happy Birthday, Michelle!
The cake looks amazing, and 34 is definitely early 30s.
Hope you have a sweet day!
OH MY! WHAT A CAKE! I’m making the snickers one right now, and I would absolutely change it for this one if peanut butter cups were sold here.
Happy B-day BEB you’re the best! And don’t worry according to my mum until 50 you’re still very very young haha ;)
Happy Birthday! This cake looks amazing! Not only beautiful but yummy too!
Happy Birthday Michelle! That looks so damn good. Enjoy your day that will be filled with joy any way you can get it.
Oh my word, this cake is one of the most beautiful things I have seen!!!! It looks so delicious!!!
Dear Michelle, just tell everyone you’re celebrating the 13th anniversary of your 21st birthday :)
(I’m on my 35th anniversary)
Nooooo! Don’t even tempt me like this.
Peanut butter + chocolate is my absolute weakness. I can only imagine how amazing this cake is!
Happy Birthday!
Happy Happy Birthday!!! Hope you have a wonderful day and year!! And no way you are in your mid-thirties yet. This cake is perfect for celebration and can’t wait to try.
HAPPY BIRTHDAY, MICHELLE!!
Happy birthday, Michelle!!!! Well, let me just say…..you are a mere baby, and not yet in your mid-thirities. I just turned 60-the new 40. That is my story and by golly-I am sticking to it! The cake looks……I don’t have words!!! Enjoy your special day!
None of my birthdays bothered me quite as much as when I turned 44. I realized I’d been married half my life and had two sons, one in his 20’s. Happy Birthday. Age is a relative thing anyway. I had a birthday 3 weeks ago and I’m not way over the hill!!!
Happy Birthday Michelle! I totally understand the comparison making between self and mom. My mom…got married on her 16th birthday and had my brother the next year the day before her 17th birthday. My brother made her a grandma @ age 38. (And my parents are still happily married…how awesome is that???) Me…I got married at 40 and miraculously became a 1st time mommy at 43. We all have to live our lives within the windows of opportunity that our life presents. I have pegged myself “the late bloomer”! Enjoy and no, I won’t tell you that you’ve hit the mid-thirties…LOL!
Happy Birthday! Love, love, love your blog and the cake looks incredibly scrumptious!! God bless you~Enjoy!!
Happy birthday!! This cake looks like I need to eat it RIGHT NOW. And no, not mid-30’s yet ;)
Happy birthday! That cake looks scary good! Enjoy