Name: Chocolate Peanut Butter Cake for a Crowd Recipe
Prep time: 30 min
Cook time: 45 min
Total time: 3 h 15 min
Cuisine: American
Ingredients: 1 3/4 cups plain / all-purpose flour; 3/4 cup unsweetened cocoa powder; 1 1/2 tsp baking powder; 1 1/2 tsp baking soda (bi-carb soda); 2 cups white sugar (or caster/superfine sugar); 1 tsp cooking/kosher salt; 2 large eggs; 1 cup milk (low or full fat); 1/2 cup vegetable oil (or plain flavoured oil like canola, grapeseed, rapeseed, sunflower); 2 tsp vanilla extract; 2 tsp instant coffee powder (optional); 1 cup boiling water; 250g / 2 sticks unsalted butter, softened; 4 cups (500 g) soft icing sugar / powdered sugar, sifted; 1/2 cup (120 g) smooth peanut butter (spread, not pure); 1/4 tsp cooking/kosher salt; 1 tbsp milk; 1/2 cup chocolate chips or melts (semi-sweet chips); 2 tbsp cream (thickened/heavy or pure, not low fat); 3 tbsp peanut butter (warmed in microwave to make it runny); 120g / 4 oz mini Reece’s Peanut Butter Cups; 10+ miniature Reece’s Peanut Butter Cups, halved; 1/4 cup salted peanuts, finely chopped

If you’re looking to wow a crowd with something totally unforgettable, then you absolutely have to try this Chocolate Peanut Butter Cake for a Crowd Recipe. I promise this cake is not just a dessert; it’s an experience. Imagine rich, moist chocolate cake layered with fluffy peanut butter frosting, topped with Reece’s Peanut Butter Cups and finished with a decadent drizzle of chocolate and peanut butter. It thrills every time—perfect for parties, potlucks, or any occasion where you want dessert to be a showstopper.

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Why You’ll Love This Recipe

Feeds a Crowd Easily: This recipe makes enough cake to serve 20 to 25 people, perfect for any large gathering.
Perfect Balance of Flavors: The rich chocolate and creamy peanut butter frosting work perfectly together without overwhelming each other.
Simple Ingredients, Big Impact: You probably have most of what you need in your pantry already, and the method is straightforward.
Crowd-Pleaser Every Time: My family goes crazy for this cake, and I’ve never seen leftovers last long!

The image shows nine thick square pieces of chocolate cake arranged on white parchment paper over a white marbled surface. Each cake piece has two layers: a dark, moist chocolate base and a thick, creamy peanut butter-colored frosting on top. The frosting is rich and smooth with swirls of glossy dark chocolate sauce drizzled over it. Pieces of peanut butter cups and chopped peanuts are scattered generously on each slice, adding texture and contrast. A silver spoon rests in a small white bowl filled with dark chocolate sauce at the top, and a woman's hand reaches into one of the cake squares. The whole scene looks delicious and indulgent with a mix of smooth and chunky textures. photo taken with an iphone --ar 2:3 --v 7 - Chocolate Peanut Butter Cake for a Crowd, large party chocolate peanut butter dessert, easy crowd-pleasing chocolate cake, decadent peanut butter chocolate cake, party dessert recipes

Ingredients You’ll Need

These ingredients come together beautifully to create a rich, moist chocolate cake with that incomparable peanut butter frosting. I always recommend using good-quality cocoa powder for that deep chocolate flavor and smooth peanut butter (not pure natural stuff) to get that creamy, slightly sweet balance.

Flat lay of rich unsweetened cocoa powder, smooth peanut butter spread in a small dollop, glossy semi-sweet chocolate chips, halved miniature Reece’s Peanut Butter Cups showing their creamy centers, finely chopped salted peanuts scattered lightly, softened unsalted butter blocks, fluffy white powdered sugar dusted gently around, and whole large brown eggs, all beautifully arranged with natural shadows, placed on a white marble surface, photo taken with an iphone --ar 2:3 --v 7 - Chocolate Peanut Butter Cake for a Crowd, large party chocolate peanut butter dessert, easy crowd-pleasing chocolate cake, decadent peanut butter chocolate cake, party dessert recipes

Flour: Plain or all-purpose flour works great to give this cake structure and the right crumb.
Cocoa Powder: Using unsweetened cocoa powder here really makes the chocolate pop—don’t skip it!
Baking Powder & Baking Soda: These leavening agents help the cake rise just right to get that perfect tender crumb.
Sugar: White sugar (caster or superfine if you have it) dissolves well for a smooth batter.
Salt: I know it sounds funny in a cake, but a little kosher salt balances sweetness and enhances flavor.
Eggs: Adds richness and helps bind the batter together.
Milk: You can use low or full-fat milk, whichever you prefer—full-fat adds extra richness.
Vegetable Oil: Any plain-flavored oil like canola or sunflower gives the cake moisture without overpowering flavors.
Vanilla Extract: Adds warmth and depth to the flavor.
Instant Coffee Powder (Optional): This is my secret weapon to intensify that chocolate flavor without tasting like coffee.
Boiling Water: Helps “bloom” the cocoa powder, making the chocolate taste more intense.
Unsalted Butter (Softened): Key for the luscious peanut butter frosting texture.
Icing Sugar: Sifted to keep the frosting silky smooth.
Smooth Peanut Butter (Not natural): Gives a sweet and creamy peanut butter flavor that blends perfectly with the frosting.
Salt for Frosting: Just a pinch to bring everything together.
Milk for Frosting: Helps adjust frosting consistency for easy spreading.
Chocolate Chips or Melts: Use semi-sweet for that rich chocolate drizzle on top.
Cream: Heavy or thickened cream makes the drizzle silky and shiny.
Peanut Butter (Warmed): Warming it helps you drizzle easily and get that beautiful finish.
Mini Reese’s Peanut Butter Cups: Both whole and halved for decoration that brings texture and extra peanut buttery goodness.
Salted Peanuts (Finely Chopped): Adds a delightful crunch and a salty touch to balance the sweetness.

Note: You’ll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Variations

One of the things I love most about this Chocolate Peanut Butter Cake for a Crowd Recipe is how easy it is to tweak it to your taste or dietary needs. Don’t hesitate to get creative and make this cake truly yours!

Gluten-Free Version: I’ve swapped in a gluten-free all-purpose blend before with great results—just make sure your baking powder is gluten-free too.
Nut-Free Alternative: For friends with nut allergies, use sunflower seed butter instead of peanut butter and skip the Reese’s toppings; sunflower butter still gives a nutty vibe without nuts.
Extra Chocolatey: I’ve added a handful of chocolate chunks inside the batter for extra melty bites that people rave about.
Salted Caramel Twist: Sometimes I drizzle salted caramel on top with the chocolate and peanut butter for an indulgent twist that’s irresistible.

How to Make Chocolate Peanut Butter Cake for a Crowd Recipe

Step 1: Prep Your Pan and Oven

Begin by preheating your oven to 180°C (350°F). I like to grease a 9 x 13-inch metal cake pan with butter, then line it with parchment paper that has an overhang. This trick makes it so much easier to lift the cake out once it’s cool. Trust me, it saves a lot of headaches later!

Step 2: Mix the Dry Ingredients

In a large bowl, sift together the flour, cocoa powder, baking powder, baking soda, sugar, and salt. If you don’t sift, you might get little clumps of cocoa powder or powdered sugar in your batter, and that’s no fun. Once sifted, give it a good whisk to make sure everything is evenly distributed.

Step 3: Add the Wet Ingredients and Coffee Magic

Next, add the eggs, milk, vegetable oil, and vanilla extract to the dry ingredients. If you decide to use instant coffee powder (and I highly recommend it!), stir it in now—it magically amps up the chocolate flavor without making the cake taste like coffee. Then pour in the boiling water and stir gently. This step makes your chocolate “bloom,” giving the cake richer depth. The batter will be thin, but that’s exactly what you want.

Step 4: Bake to Perfection

Pour the batter into your prepared pan and pop it into the oven for about 45 minutes. You’ll know it’s done when a toothpick inserted comes out clean or with just a couple of moist crumbs. Avoid overbaking—it’s how I learned to keep the cake moist and tender every time.

Step 5: Whip Up the Peanut Butter Frosting

While the cake cools completely, it’s time for the frosting. Beat the softened unsalted butter until it’s fluffy, then gradually add sifted icing sugar. Add the smooth peanut butter along with that pinch of salt and a tablespoon of milk to get the consistency just right for spreading. If your frosting looks too stiff, a tiny splash more milk will loosen it up—add sparingly so you don’t get it too runny.

Step 6: Assemble and Decorate Like a Pro

Spread the peanut butter frosting evenly over the cooled cake. Now, sprinkle the finely chopped salted peanuts for a surprising crunch. Melt the chocolate chips with the cream to create a glossy drizzle, then warm peanut butter separately and combine to drizzle over the top—this little finishing touch will have your guests oohing. Scatter the mini Reese’s Peanut Butter Cups all over—the halved ones make the cake look extra pretty and invite everyone to dig in.

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Pro Tips for Making Chocolate Peanut Butter Cake for a Crowd Recipe

Bloom Your Cocoa: Mixing the boiling water in releases all that deep chocolate flavor, so don’t skip this step.
Use Room Temperature Ingredients: It helps the batter come together easily and ensures the frosting is smooth and fluffy.
Slowly Add Icing Sugar to Frosting: This avoids a gritty texture and gives you that perfectly silky frosting.
Don’t Frost Warm Cake: Frosting melts if the cake isn’t completely cool—plan ahead to avoid a messy situation!

How to Serve Chocolate Peanut Butter Cake for a Crowd Recipe

A slice of rich dark chocolate cake with a thick, creamy light brown peanut butter frosting layer on top, decorated with chopped peanut butter cups and whole peanuts. The frosting is drizzled with dark chocolate sauce. The cake is placed on a white plate with a few scattered peanuts around. A woman's hand holding a fork is cutting into the moist cake, lifting a piece. The background is a white marbled texture. Photo taken with an iphone --ar 2:3 --v 7 - Chocolate Peanut Butter Cake for a Crowd, large party chocolate peanut butter dessert, easy crowd-pleasing chocolate cake, decadent peanut butter chocolate cake, party dessert recipes

Garnishes

I love using mini Reese’s Peanut Butter Cups for garnish because they add a nostalgic and fun peanut butter punch. Finely chopped salted peanuts give a fantastic contrast in texture and a little salty balance to all that sweetness. Sometimes I’ll also sprinkle a tiny pinch of flaky sea salt on top of the drizzle—it really makes the flavors pop and keeps everyone coming back for more.

Side Dishes

If you’re serving this cake along with other treats, lighter options like fresh berries or a simple mixed greens salad with a citrus vinaigrette help cut through the richness. For drinks, I’m a sucker for cold milk or a strong black coffee to balance the indulgence.

Creative Ways to Present

For larger celebrations, I’ve previously placed this cake on a rustic wooden board surrounded by clusters of whole peanuts and additional Reese’s cups for that rustic-chic look. Another favorite is serving the cake in neat squares on colorful plates, each topped with a mini peanut butter cup and a drizzle of extra chocolate. It’s a guaranteed conversation starter and makes slice-serving a breeze!

Make Ahead and Storage

Storing Leftovers

I usually store leftovers covered tightly in the fridge—this cake lasts really well for 3 to 4 days. The frosting firms up a bit, which I personally love. Just bring slices to room temp before serving to get that luscious peanut butter softness back.

Freezing

If you want to make this cake ahead of time, it freezes beautifully. I freeze it in the pan, wrapped well in plastic wrap and foil, for up to 2 months. When you’re ready to serve, thaw overnight in the fridge and then finish with the fresh peanut butter/ chocolate drizzle and toppings.

Reheating

I usually don’t heat this cake, since it’s best enjoyed cool or room temperature. But if you want a warm bite, a quick 10-second zap in the microwave really brings out the gooey peanut butter flavor—just don’t overdo it or the frosting will melt completely.

FAQs

Can I make this cake in round pans instead of a sheet pan?

Absolutely! You can divide the batter evenly between two 9-inch round pans. Just adjust the baking time slightly, checking with a toothpick around 35-40 minutes. The layer cakes also look great stacked with frosting between them.
Is the instant coffee powder necessary?

It’s not required but highly recommended! The coffee enhances the chocolate flavor without leaving a coffee taste. If you prefer, you can omit it without affecting the cake’s texture.
Can I use natural peanut butter instead of smooth peanut butter?

Natural peanut butter has a much stronger flavor and different texture, which may affect the frosting consistency. For best results, I suggest using smooth, spreadable peanut butter for a balanced taste and creamy frosting.
How do I prevent the frosting from being gritty?

Sifting the icing sugar and slowly adding it while beating really helps achieve that silky frosting. Also, mixing butter and peanut butter until smooth before adding sugar makes a huge difference.
What’s the best way to cut and serve this cake?

I recommend cutting it into smaller pieces since it’s rich and decadent—you’ll want to offer 20-25 slices from this recipe. Using a sharp serrated knife and wiping it between cuts helps keep clean edges.

Final Thoughts

This Chocolate Peanut Butter Cake for a Crowd Recipe is one I reach for whenever I want to impress without stress. It’s become a favorite among my friends and family, and every time I serve it, I see happy smiles all around the room. The ease of making a big batch that tastes like it took hours is a total win in my book. Give this one a go—you’ll be so glad you did!