Unbelievable Reese’s Peanut Butter Earthquake Cake Has Only 7 Ingredients

Oh my goodness, let me tell you about the first time I made this Reese’s peanut butter earthquake cake – it was love at first bite! Picture this: rich chocolate cake swirled with gooey peanut butter filling, topped with melty Reese’s cups and chocolate chips. It’s like all my favorite candy bar flavors decided to throw a party in one pan.

What makes this recipe so special? It’s ridiculously easy (we’re talking box mix easy) but tastes like you spent hours in the kitchen. The “earthquake” part happens when the peanut butter layer sinks into the batter while baking, creating these amazing pockets of peanut butter goodness. Trust me, I’ve brought this to potlucks and watched grown adults literally elbow each other out of the way for seconds.

My kids beg me to make this for their birthdays now instead of traditional cake. And honestly? I don’t blame them. There’s something magical about that chocolate-peanut butter combo that makes everyone’s eyes light up. Whether you’re feeding a crowd or just treating yourself (no judgment here), this Reese’s peanut butter earthquake cake never disappoints.

The Must-Have Ingredients for Your Peanut Butter Earthquake Cake

Gathering the right ingredients is what makes this Reese’s peanut butter earthquake cake so dangerously good. Here’s everything you’ll need – and trust me, the simpler the better when it comes to this recipe!

For the cake base:

• 1 box devil’s food cake mix (my go-to for extra chocolatey goodness)
• 1 cup water
• 1/2 cup vegetable oil
• 3 large eggs (room temperature works best)

The peanut butter earthquake layer:

• 1 cup peanut butter – creamy or crunchy (I’m team creamy all the way)
• 1 cup powdered sugar
• 1/2 cup melted butter

The glorious toppings:

• 1 cup Reese’s peanut butter cups, chopped (I like mini ones for easier chopping)
• 1/2 cup semi-sweet chocolate chips

See? Nothing fancy – just pantry staples and our favorite candy. But put them together and magic happens!

How to Make Reese’s Peanut Butter Earthquake Cake

Okay, buckle up – we’re about to make magic happen! This Reese’s peanut butter earthquake cake comes together so easily, you’ll be tempted to make it every weekend (I won’t tell if you do). Just follow these simple steps and get ready for the most delicious “earthquake” you’ll ever experience!

Step 1: Prepare the Cake Batter

First things first – preheat that oven to 350°F (175°C). While it’s warming up, grab your favorite 9×13-inch baking dish and give it a good greasing. I like to use butter or baking spray – enough to make sure nothing sticks to the sides.

Now, in a large mixing bowl, combine the chocolate cake mix, water, oil, and eggs. Mix it just until everything comes together smoothly – about 2 minutes with an electric mixer or 3-4 minutes by hand. Don’t go crazy mixing; we want tender cake, not tough! Pour this luscious chocolate batter into your prepared pan, smoothing it out evenly with a spatula.

Step 2: Add the Peanut Butter Layer

Here’s where the fun begins! In another bowl, mix together the peanut butter, powdered sugar, and melted butter until you’ve got this thick, dreamy peanut butter paste. Now grab a spoon and start dropping dollops of this mixture all over the chocolate batter. Don’t worry about making it perfect – the “earthquake” happens when these peanut butter blobs sink and swirl as the cake bakes!

Step 3: Top with Reese’s and Chocolate Chips

The grand finale! Sprinkle those chopped Reese’s cups and chocolate chips evenly over the top. I like to use my hands for this part – it lets me distribute everything just right. Pro tip: save a few pieces to press lightly into the center where they’ll get extra gooey. Pop that beautiful creation into the oven and bake for 30-35 minutes. You’ll know it’s done when the top looks set and a toothpick inserted near the center comes out with just a few moist crumbs (not wet batter).

Now comes the hardest part – waiting for it to cool before digging in! The peanut butter filling stays molten hot at first, so give it at least 15 minutes. I promise, the anticipation makes that first bite even better.

Tips for the Best Reese’s Peanut Butter Earthquake Cake

After making this cake more times than I can count (no regrets!), I’ve picked up some tricks that take it from good to “oh-my-word-I-need-the-recipe” amazing. Here’s what I’ve learned:

Room temperature eggs are your friend – they blend into the batter more evenly than cold eggs straight from the fridge. I usually set mine out when I preheat the oven.

Don’t overmix the batter – stir just until everything’s combined. Overworked batter makes the cake dense instead of light and fluffy. A few small lumps are totally fine!

Check your oven temp – I learned the hard way that my oven runs hot! An inexpensive oven thermometer helps prevent overbaking. The cake should jiggle slightly when you take it out – it’ll set as it cools.

Chop those Reese’s cups small – about pea-sized pieces distribute better and prevent huge chunks that might sink completely to the bottom.

Let it cool before serving – I know it’s tempting, but that peanut butter layer stays dangerously hot! Waiting 15-20 minutes means perfect slices instead of molten lava cake (though that doesn’t sound terrible either…).

Ingredient Substitutions and Variations

One of the best things about this Reese’s peanut butter earthquake cake is how easily you can tweak it to suit your tastes or what’s in your pantry! Here are some of my favorite swaps:

Out of peanut butter? Almond butter works surprisingly well – it gives a slightly nuttier flavor that’s delicious with the chocolate. For a fun twist, try using Nutella instead of peanut butter for a chocolate-hazelnut version (just reduce the powdered sugar since Nutella’s sweeter).

Not a Reese’s fan? (Gasp!) Try chopped Snickers, Butterfingers, or even peanut butter M&Ms instead. For nut allergies, sunflower seed butter works great – just skip the peanut butter cups and use extra chocolate chips or crushed Oreos on top.

Want to go homemade? Swap the box mix for your favorite chocolate cake recipe – just keep the liquid amounts similar. The possibilities are endless!

Storing and Reheating Reese’s Peanut Butter Earthquake Cake

Here’s the best part – this cake actually gets even better the next day as the flavors mingle! I just cover it tightly with foil or plastic wrap and leave it at room temperature for up to 3 days. If you want to freeze it (trust me, future you will thank you), wrap individual slices in plastic, then foil, and they’ll keep beautifully for 2-3 months.

When that peanut butter craving hits, pop a slice in the microwave for 15-20 seconds – just enough to make the chocolate chips glossy again. The peanut butter layer gets all ooey-gooey, just like fresh from the oven!

Frequently Asked Questions

Can I use homemade cake mix instead of boxed?
Absolutely! Just use your favorite chocolate cake recipe that makes a 9×13-inch cake. The key is keeping the liquid amounts similar so the “earthquake” effect still happens with the peanut butter layer.

How do I know when it’s done baking?
The top should look set and the edges slightly pulled away from the pan. My grandma’s trick? Gently press the center – it should spring back lightly. A toothpick should come out with moist crumbs, not wet batter.

Can I make this without peanut butter cups?
Of course! While Reese’s make it extra special, you can skip them and just use chocolate chips. Or get creative with other mix-ins like chopped nuts or marshmallows.

Why did my peanut butter layer sink to the bottom?
That’s exactly what’s supposed to happen! The “earthquake” creates those delicious peanut butter pockets throughout the cake. If it all sank completely, your batter might have been too thin – try reducing the liquid slightly next time.

Can I make this in a different pan size?
Yes, but adjust baking times accordingly. A 9-inch square pan will need about 5 extra minutes, while cupcakes bake in 18-20 minutes. Just watch for those visual cues!

Nutritional Information

Just between us – this Reese’s peanut butter earthquake cake isn’t exactly health food (but who wants that when chocolate and peanut butter are involved?). The nutritional values will vary depending on which brands of ingredients you use and how big you cut those slices. My advice? Enjoy every delicious bite and save the math for another day!

Rate This Recipe

Did you make this Reese’s peanut butter earthquake cake? I’d love to hear how it turned out! Leave a quick rating below or snap a photo of your creation – nothing makes me happier than seeing your chocolate-peanut butter masterpieces!

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