Peanut Butter Cup Brownies have a gooey brownie base, peanut butter cups, and a rich peanut butter-chocolate topping for a show-stopping dessert.
author’s note
Peanut Butter + Chocolate = The Best Brownies Ever!
Every Halloween, I snag all the extra Reese’s from my kids’ candy bags (plus whatever’s left from handing out candy) and we turn them into these peanut butter cup brownies. It’s one of our favorite traditions now.
My kids even grab way more than they need just so we have extras to bake with. If we’re in a hurry, I’ll pull out a boxed brownie mix, but if the kids are in baking mode, we go all in with my recipe for the fudgiest homemade brownies.
Peanut Butter Cup Brownies Ingredients
| Ingredient | Why It Matters / Swaps |
|---|---|
| Brownie mix (9 × 13 in. size) | Any brand works. Make it from scratch too; just keep the pan size. |
| Eggs, oil, water | Follow the box. Try melted butter or cooled coffee for deeper flavor. |
| Original-sized Reese’s cups | Large cups give generous PB pockets. Mini cups or chocolate-hazelnut cups also work. |
| Milk chocolate chips | Classic sweetness. Swap semi-sweet or dark to reduce sugar. |
| Creamy sweetened peanut butter | Avoid natural PB; texture separates. |
| Coconut oil or shortening | Helps chocolate melt smoothly; butter works in a pinch. |
Fun Variations
- Bake in muffin tins for brownie “cups.”
- Swirl ¼ cup peanut butter into the batter for ripples.
- Sprinkle flaky sea salt over the warm topping.
- Fold chopped salted peanuts into the topping for crunch.
How To Make Peanut Butter Cup Brownies
- Prep Pan: Line a 9 × 13 in. pan with parchment and heat the oven per the mix.
- Mix & Bake: Make the batter and bake two minutes less than the box says.
- Add Cups: Gently press pb cups into the soft top, then bake two more minutes.
- Top It: Cool completely. Melt chocolate with one tablespoon oil and spread over brownies. Melt peanut butter with the remaining oil, drizzle, and marble.
- Set & Slice: Let the topping firm up, then slice with a hot knife for clean edges.
Tips For Success
- Use room-temperature eggs for a shinier crust.
- Melt chocolate in 20-second microwave bursts, stirring well between rounds.
- No peanut butter cups on hand? Press peanut butter chips plus a drizzle of warm PB into the half-baked brownies.
Quick Tip
Streaky or spotty chocolate is simply the cocoa solids separating out and rising to the top. If the brownies do end up with white spots, they are still perfectly safe to consume.
Storage
Peanut Butter Cup Brownie Storage
Room temperature: Cover tightly and enjoy within four days.
Freezer: Wrap squares in parchment, place in a zip bag, and freeze up to two months. Thaw at room temp; white “bloom” on the chocolate is normal.
More Chocolate-Peanut Butter Recipes:
Desserts
No Bake Peanut Butter Cheesecake
Desserts
Peanut Butter Cookie Dough
Desserts
Peanut Butter Brownie Bites
Peanut Butter Cup Brownies
Peanut Butter Cup Brownies are indulgent treats—gooey brownies loaded with peanut butter cups and topped with a rich, fudge-like peanut butter chocolate layer.
Ingredients
- 1 (18.3-ounce) package fudge brownie mix plus ingredients called for on the brownie mix, see note 1
- 15 regular-sized Reese’s peanut butter cups unwrapped
- 2-1/2 cups milk chocolate chips
- 3/4 cup creamy peanut butter I love Skippy
- 1 teaspoon vanilla extract optional
- 2-1/2 tablespoons shortening or coconut oil, divided
Instructions
- Line a 9×13-inch pan with parchment paper and set aside. Preheat oven according to brownie mix instructions.
- Prepare the brownies according to package directions. Pour the mixture into the prepared pan and bake for 2 minutes less than the package directs. Meanwhile, unwrap the peanut butter cups.
- Working quickly, press the unwrapped peanut butter cups evenly into the brownies—3 rows of 5 each.
- Return the brownies to the oven and bake for the remaining 2 minutes. Remove and allow to fully cool to room temperature. If you refrigerate or freeze them, allow them to come back to room temperature before topping with the melted chocolate (otherwise you’ll risk streaky/spotty chocolate—see note 2).
- In a microwave-safe bowl, combine the chocolate chips and 2 tablespoons (23g) of shortening or coconut oil. Microwave in bursts of 20 seconds, stirring between bursts for 20 seconds until the chocolate is completely melted (see note 3). Melt slowly, stirring well between bursts to avoid burning chocolate. Use a spatula to scrape every bit of the chocolate onto the cooled brownies. Smooth the chocolate into an even layer.
- In another small microwave-safe bowl, combine the peanut butter and remaining 1/2 tablespoon (6g) coconut oil or shortening. Microwave for 30 seconds. Remove and stir until smooth. If desired, stir in the vanilla extract. Pour in long stripes over the melted chocolate. Using a knife, marble the top by running the knife horizontally from left to right just through the top chocolate and peanut butter layers. Don’t go deep enough to hit the brownies.
- Allow brownies to completely set up at room temperature (do not chill!) before enjoying the bars. Cut into bars—this can get a little messy! I recommend using a sharp knife and running it under hot water for 10 seconds, drying it off, then making a cut. Repeat this process for each cut. Use a metal spatula to remove brownies.
Video
Recipe Notes
Note 1: I love Betty Crocker’s Fudge Brownie Mix best in this recipe. Be sure that whatever brownie mix you use, it will bake properly in a 9×13-inch pan.
Note 2: If the brownie base is chilled when the chocolate is added on top, it can cause spotty or streaky chocolate. Additionally, if the brownies are chilled after adding the chocolate and peanut butter topping, it makes these brownies very difficult to cut out—the top cracks instead of cutting smoothly. Finally, I think these brownies taste best at room temperature, not chilled. If you do end up with streaky or spotty chocolate, it’s perfectly safe to eat; this is simply cocoa solids separating and rising to the top.
Note 3: Keep in mind that chocolate is still melting even after it has been removed from the microwave. I like to microwave it as little as possible, focusing instead on stirring to melt the chocolate with residual heat.
Nutrition Note: Nutrition information does not include the ingredients called for in the brownie mix, since that will vary by brand.
Storage: Enjoy these bars within 3–5 days. Store tightly covered at room temperature; no refrigeration needed. Freeze if desired, but thawing may cause harmless white spots from separated milk solids.
Nutrition
Serving: 1serving | Calories: 208kcal | Carbohydrates: 24g | Protein: 4g | Fat: 11g | Saturated Fat: 4g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 5g | Cholesterol: 1mg | Sodium: 136mg | Potassium: 85mg | Fiber: 1g | Sugar: 17g | Vitamin A: 6IU | Vitamin C: 1mg | Calcium: 11mg | Iron: 1mg
Nutrition information is automatically calculated, so should only be used as an approximation.
Just a warning to everyone….the boxed brownies are no longer 18.3 ounces but 16.3, shrink-flation as we all call it, as I post this. This will affect the base of this recipe and it will be much flatter. I am not sure if there is an easy solution other than trying a smaller pan and reduce the other ingredients.
*If anyone has a solution that has worked, please let me know.
Dang shrink-flation! You can still get some that are 17.8 oz so that’s what I would recommend. It doesn’t seem to make too big of a difference! Thanks Susan!
I really wish that you would put the option to save to Pinterest on these recipes. It’s a pain to have to go to Pinterest and hunt them down . Thank you
At the top of each post there is a P that you can click and pin! I hope this helps!
This was a success. I have a peanut butter / chocolate loving family. Easy to make and delicious.
I am so thrilled to hear this! Thanks Lynn! 🙂
YUMMMMM!!!!!
Thanks Penny!
what brand of brownie mix do you use. Thank you.
The two mixes that I like best in this recipe: Betty Crocker’s Supreme Triple Chunk ®(17.8 ounces) or Ghirardelli Chocolate Triple Fudge Brownie Mix® (19 ounces).
I just wanted you to know that I’ve made these many times over the years and they are always a big hit. Thank you so much for the recipe!
Awe so happy to hear that, thanks Rachel!!
These are the best brownies I’ve ever made! Making them again for a party on Sunday!
I’m so happy to hear! Thanks! 🙂