This Peanut Butter Cup Earthquake Cake recipe is made with Reese's, peanut butter frosting made from scratch as a rich filling, and chocolate cake mix – so moist and rich! Tastes just like the popular candy, but in a decadent dessert.
A great big happy early birthday to my husband, Noah, whose actual birthday is Thursday! Today, I'm sharing my go-to birthday cake for him. I've made it several years and it's a hit each and every time.
And not just a hit with my family. Almost 3 years ago to the day, I published the first edition of this Peanut Butter Cup Earthquake Cake recipe on my blog. It went viral almost immediately and, to this day, it is the most popular among hundreds of recipes on my this site. It even inspired a whole series of Earthquake Cake recipes (see how you can snag them all at once below).
But here's the thing – I never thought it would be so big! The pictures in the original post honestly kind of stunk – I just snapped them with my iPhone as I made it in case I did decide to share on the blog. You can still see the original photos at the end of the post (warning: they're not good). The post needed some TLC in a bad way, especially since it was the first thing a lot of people see on Lamberts Lately.
So, I'm giving that makeover today! New photos, new video, a slightly altered recipe, and a prettier layout. Still a delectable, moist chocolatey, peanut-buttery cake that is as good as ever.
Peanut Butter Cup Earthquake Cake
(printable version of this recipe at the bottom)
- 1 box of Devil's Food cake mix
- 4 eggs
- 1 cup milk
- 2 cups peanut butter
- 2 sticks butter, softened to room temperature
- chocolate syrup
- ¼ cup milk
- 2 cups powdered sugar
- 30 chopped Reese's peanut butter cups (this size) – the 12oz bag is almost perfect for this recipe
Directions
In a large bowl, mix together cake mix, eggs, 1 cup milk, 1 cup of peanut butter, and 1 stick of butter. Spread mixture in a greased 9×13″ baking dish.
Bake cake for 35-40 minutes at 350 degrees.
Peanut Butter Cup Earthquake Cake
Ingredients
- 1 Box of Devil's food cake mix
- 4 eggs
- 1 cup milk
- 2 cups peanut butter
- 2 sticks butter softened to room temperature
- chocolate syrup
- 1/4 cup milk
- 2 cups powdered sugar
- 30 chopped miniature peanut butter cups
Instructions
- In a large bowl, mix together cake mix, eggs, 1 cup milk, 1 cup of peanut butter, and 1 stick of butter. Spread mixture in a greased 9x13" baking dish.
- With a mixer, mix together 1 stick butter, 1 cup peanut butter, and 1/4 cup milk. Slowly add in powdered sugar until frosting is mixed well.
- Spoon half of the frosting mixture on top of the cake mix. Add 6-8 large squirts of chocolate syrup.Very gently swirl frosting and syrup into the cake mix. Don't completely mix. Make sure you get swirls into the edge of the cake pan.
- Gently press in half of the chopped peanut butter cups.
- Bake cake for 35-40 minutes at 350 degrees.Top cake with remaining frosting, more chocolate syrup, and remaining chopped peanut butter cups.
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Enjoy! You can catch my other recipes here or see the Earthquake Cake collection posts here.
Images from a previous version of this post…
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Do you put the icing on while it is still hot or do you let it cool first?
You can do it either way…I put mine on when it was slightly warm and it kind of melted into the nooks and crannies!
can this be made using a chocolate cake mix?
Absolutely! It would obviously change the flavor a little, but should work just fine.
Is it supposed to be gooey in the middle from the frosting swirled in?
It might be, just at the parts that have the frosting. It should be fairly well-set once it cools!
Refrigerate?
It wouldn’t hurt – I did when I first made it. With the butter and milk in the icing there’s a potential for it to go bad.
Mine took a lot longer to cook, and the middle still didn’t set. The edges were delicious. I guess I need to try again. Lol
It might have to do with the pan you used – was it 9×13″? Smaller pans can take longer to cook since it makes the cake thicker.
It was a glass 9×13. I rechecked the recipe several times. It was delicious around the edges so I still may try it again.
You mention 1 c milk in the recipe… in the cake portion, you are using 1 c milk and then in the frosting portion, another 1/4 c milk. Is the total 1 1/4 c milk or is it only supposed to be 3/4 c milk for the cake?
Hi there! They are listed out as two different ingredients in the recipe.
Thanks! You know how many times I looked at that?!?! Apparently it’s time to make an earthquake cake! 😉
I think I over baked! At first it wasn’t done in the middle at 35 min , I added a few more than took it out. As it cooled it kinda caved in. Hoping the frosting saves it!
It’s going to look a little undercooked in the middle at first – the icing won’t firm up like the cake part. Give it 5-10 minutes before baking more next time – it usually takes about that long for the middle to not be jiggly! If it’s still jiggly after 10 minutes, it probably needs to be baked a little bit longer.
Hey there!!! I’m allergic to chocolate, but I’m always looking for recipes that I can convert to white chocolate, and i love Reese’s peanut butter cups. This recipe looks delicious. I figure I could use the white reese’s and I could melt some white chips in place of the syrup. But what cake mix do you think would work best???
That sounds great! I’d probably recommend either a yellow cake mix or (if you can find it) a peanut butter cake mix.
can you make this cake in advance and freeze it or how to stire it
Looking over the recipe, I don’t think any ingredients would be an issue, but I can’t attest to the quality after freezing – but it’s at least worth a try!
Swapped out the store bought chocolate syrup with a homemade chocolate ganache…. just 1 cup hot cream and 1 cup chocolate chips and whisk. The whole thing was beyond decadent.
Have you ever tried making this in 2 round pans and stacking them for a birthday style cake?
I haven’t, but it should work! The cook time might need to be adjusted though.
I’m not a very big g fan of devils food cake. Do you think that could be replaced with a brownie mix or even a yellow cake mix?
Absolutely! I’ve made this with other flavors of cake mix before (I believe it was yellow), it’s just has less chocolate flavor.