Peanut Butter Brownies from Brownie Mix are definitely a winner — fudgy brownies stuffed with sweet and salty peanut butter.
You may also like Chocolate Cake with Ganache Frosting, Salted Chocolate Chunk Shortbread Cookies, M&M Cookies, or Chocolate Crinkle Cookies.
Upgrade your boxed brownies in 7 other ways:
- Cheesecake Brownie from Brownie Mix
- Brookie Bars from Brownie Mix
- Oreo Brownies from Brownie Mix
- Nutty Brownies from Brownie Mix
- S'mores Brownies from Brownie Mix
- Salted Caramel Pretzel Brownies from Brownie Mix
- Birthday Brownies from Brownie Mix
Jump to:
Ingredients you'll need
For the brownie base
Extra ingredients
Notes and substitutions
- Brownie mix: Use a regular-size (about 18 ounces) boxed brownie.
- Water: Replace with milk, buttermilk, or brewed coffee to add richness and flavor.
- Instant coffee: An optional ingredient that enhances the chocolate flavor and tames the sweetness of the brownies.
Tips for best brownies
- Bring eggs to room temperature and lightly beat them to incorporate them well without overmixing.
- Grease and line the pan with parchment paper to prevent the brownies from sticking.
- To avoid overbaking, check the brownies with a toothpick 2 minutes before they are done. Look for several separate crumbs for fudgy brownies and less for cakey brownies.
- Cool the brownies before slicing. Refrigerating them improves their texture.
How to make this recipe
Step 1: Make the brownie batter as directed in the package and spread it on a 9x9-inch pan.
Step 2: In a small bowl, combine ¾ cup peanut butter and ¼ cup powdered sugar until smooth. Warm the peanut butter in the microwave if it's too thick.
Step 3: Mix spoonfuls of peanut butter mixture into the brownie batter with a knife or skewer.
Step 4: Bake according to package instructions.
Let the brownies set for at least an hour in the fridge before cutting. Refrigerate leftovers and consume them within 5 to 7 days.
Recipe FAQs
Eggs at room temperature will blend easily with other ingredients. Baked goods will rise evenly and have a uniform texture.
Use a neutral-flavored oil for baking, such as canola or other vegetable oils. I also like mild-tasting oils like avocado oil, olive oil, and coconut oil.
Yes! You can easily double this recipe and bake it in a 9x13-inch pan.
More about brownies
If you'd like to know more, here are frequently asked questions on box brownies, including extra tips, troubleshooting, and more.
Other dessert recipes you may like
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📖 Recipe
Peanut Butter Brownies from Brownie Mix
Equipment
- 9x9-inch pan
Ingredients
For the brownie base (see package)
- brownie mix about 18 ounces
- eggs room temp & lightly beaten
- water sub:milk, buttermilk, or coffee
- oil (canola, olive, or other vegetable oils)
- ½ teaspoon instant coffee or ¼ teaspoon espresso powder optional
For the peanut butter mixture
- ¾ cup peanut butter salted (or add a pinch of salt)
- ¼ cup powdered sugar
Instructions
- Make the brownie batter as directed in the package and spread it on a 9x9-inch pan.
- In a small bowl, combine peanut butter and powdered sugar until smooth. Warm the peanut butter in the microwave if it's too thick.
- Mix spoonfuls of peanut butter mixture into the brownie batter with a knife or skewer.
- Bake according to package instructions.
- Let it set for at least an hour in the fridge before cutting.
Video
Notes
- Bring eggs to room temperature and lightly beat them to incorporate them well without overmixing.
- Grease and line the pan with parchment paper to prevent the brownies from sticking.
- To avoid overbaking, check the brownies with a toothpick 2 minutes before they are done. Look for several separate crumbs for fudgy brownies and less for cakey brownies.
- Cool the brownies before slicing. Refrigerating them improves their texture.
Cara
Oh what a great combination. I’m also thinking of mixing in some reese’s pieces..
Nora Rey
Oh, absolutely! That sounds like an amazing addition! 🤩 Combining Reese's Pieces will take it to a whole new level of deliciousness! You've got a fantastic idea there. Let me know how it turns out.