These peanut butter brownies from brownie mix are definitely a winner — fudgy brownies stuffed with sweet and salty peanut butter filling.
You can also upgrade your boxed brownies in seven 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 layer
Extra ingredients
Notes and substitutions
- Brownie mix: Use a regular-size (about 18 ounces) boxed brownie.
- Water: Use milk, buttermilk, or brewed coffee instead of water 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 the eggs to room temperature and lightly beat them to ensure they get incorporated well without overmixing.
- Grease and line the pan with parchment paper so the brownies will not stick and come out easily.
- Check the brownies two minutes before they should be done. Test with a toothpick — it should come out with several separate crumbs for fudgy brownies and less for cakey.
- Cool the brownies before slicing. Refrigerating them improves their texture.
How to make this recipe
(1)Make the brownie batter as directed in the package and spread it on a 9x9-inch pan. (2)In a small bowl, mix the peanut butter and powdered sugar until smooth. Warm the peanut butter in the microwave, if it's too thick.
(3)Mix spoonfuls of the peanut butter mixture into the brownie batter. (4)Bake as directed.
How to serve and store
Let the peanut butter brownies set for at least an hour in the fridge before cutting. Refrigerate leftovers and consume within five to seven days.
You can freeze them for up to three months if wrapped properly. Let them thaw in the fridge or at room temperature.
Frequently asked questions
Eggs at room temperature blend evenly 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 brownies including extra tips, troubleshooting, and more.
Watch how I make it here
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 instructions)
- 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 (190 grams) salted (or add a pinch of salt)
- ¼ cup powdered sugar (29 grams)
Instructions
- Make the brownie batter as directed in the package and spread it on a 9x9-inch pan.
- In a small bowl, mix the peanut butter and powdered sugar until smooth. Slightly warm the peanut butter in the microwave, if it's too thick.
- Mix spoonfuls of the peanut butter mixture into the brownie batter.
- Bake as directed.
- Refrigerate for at least an hour before cutting.
Video
Notes
- Bring the eggs to room temperature and lightly beat them to ensure they get incorporated well without overmixing.
- Grease and line the pan with parchment paper so the brownies will not stick and come out easily.
- Check the brownies two minutes before they should be done. Test with a toothpick — it should come out with several separate crumbs for fudgy brownies and less for cakey.
- Cool the brownies before slicing. Refrigerating them improves their texture.
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