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If you’re a peanut butter and chocolate person, this might become your new favorite brownie.

We aren’t talking about a subtle hint of peanut butter here, or a polite little swirl on top. This is a full-blown peanut butter takeover. We’re talking frozen peanut butter pools baked right into the batter, melty peanut butter chips in every bite, and crunchy peanut butter sandwich cookies scattered over the top. And the best part? It all starts with my viral Better Boxed Vegan Brownies method.

Dollops of peanut butter that get folded into the batter.

Why My Recipe Works

When I first developed my Better Boxed Vegan Brownies method, I was on a mission to figure out why so many vegan boxed brownies turned into either oily lava pits or sad hockey pucks. After many test batches, I cracked the code by replacing the oil with vegan butter, adding some nut butter for structure, and using an extra-thick flax egg. It delivers a rich, fudgy brownie with that classic shiny, crackly top.

My ultimate peanut butter version takes that reliable base and elevates it. Instead of swirling peanut butter into the batter and hoping for the best (which usually just results in it disappearing into the chocolate), we freeze dollops of peanut butter first. This is the ultimate game-changer. By folding them into the batter frozen, they hold their shape in the oven, creating thick, gooey pockets of pure peanut butter goodness throughout.

What You’ll Need

Boxed Brownie Mix: Most are accidentally vegan and my favorite to use are from Duncan Hines although I’ve tested many and most have worked well.
Peanut Butter Sandwich Cookies: These add the perfect nostalgic crunch on top. Nutter Butters are the classic choice and accidentally vegan, as are many store-brand sandwich cookies. I used Aldi’s Benton peanut butter sandwich cookies.
Peanut Butter Chips: This is where things get exciting. Reese’s peanut butter chips are officially dairy-free now. I actually wrote a whole post about this ingredient change here because I honestly never thought I’d see the day. If you’ve been avoiding them, welcome back to your baking era.

Tips for Success

Freeze the peanut butter solid. This is non-negotiable if you want those distinct, gooey pools instead of a messy swirl.
Stick to conventional creamy peanut butter. The super-natural, separated kinds don’t freeze as well and tend to melt right into the batter.
Keep your cookie chunks big. You want recognizable, crunchy cookie pieces on top, not fine dust.
Don’t skip the vegan butter. It’s essential to the chemistry of my method. It provides a much richer flavor and texture than standard vegetable oil.

Frequently Asked Questions

Yes, many mainstream and store brands (like Nutter Butter) are accidentally vegan! Just be sure to double-check labels, as recipes can change.

They sure are. I reported the news in September 2025 and they can be found at Walmart and many regional grocery stores. It still feels wild to type that, but it’s one of the biggest wins for vegan baking I’ve seen in a long time.

My favorite brand to use is Duncan Hines and especially Dolly Parton’s fudgy brownie mix. I used Aldi’s Specially Selected double chocolate mix testing this recipe though and it worked great. It has chocolate chips added and I enjoyed that. You can certainly add some to the batter along with the peanut butter chips.

This usually happens if the peanut butter wasn’t frozen completely solid before baking, or if the batter was over-mixed after folding them in.

Yes! You can add regular chocolate chips like I mentioned above or buy a mix that has them in there already, and you can try adding chopped roasted peanuts if you want to amp up the peanut flavor even more!

If you’re ready for the ultimate peanut butter brownies, look no further. From the melty peanut butter chips, to the crunchy cookies on top, to the frozen peanut butter pockets that actually deliver on maximum PB flavor, this is your sign to bake a batch. It’s peak peanut butter and chocolate energy in the absolute best way.

More recipes using my better boxed brownie base!

Ultimate Peanut Butter Brownies

Recipe by Kreg

5.0 from 1 vote

Course: Sweets, DessertCuisine: AmericanDifficulty: Easy

Servings

servings

Prep time

minutes

Cooking time

minutes

Fudgy vegan brownies made with my Better Boxed method, packed with dairy-free Reese’s peanut butter chips and chunks of peanut butter cookies and pockets of peanut butter mixed in for the ultimate peanut butter chocolate treat.

Cook Mode

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Ingredients

Boxed Brownies
1 box brownie mix 16-18 oz that are vegan by ingredients
1/4 teaspoon baking powder
1/4 cup vegan butter, melted
1/4 cup peanut butter (see notes)
1/3 cup water
3 tablespoons finely ground flax meal mixed into 1/4 cup room temperature water
1/2 cup Reese’s dairy free peanut butter chips
5-6 peanut butter sandwich cookies
Frozen Peanut Butter Drops
1/3 cup creamy peanut butter
3 tablespoons powdered sugar

Directions

Make the frozen peanut butter drops
Mix the peanut butter and powdered sugar well in a small bowl then using a teaspoon, drop small dollops on a small baking sheet lined with parchment or wax paper and freeze for a least and hour to fully solidify.
Preheat oven to 350°. Butter or spray (I prefer to butter pans) a 9” square baking pan and set aside.
Whisk the flaxmeal into the water and set aside to thicken for 3-5 minutes.
Open the brownie mix and empty into a large bowl. Whisk in the baking powder then add the rest of the ingredients and the flax egg and beat with a hand mixer or for about 50 strokes by hand until completely blended and glossy. Add in half of the peanut butter chips then add the frozen peanut butter dollops and fold carefully into the batter being careful not to aggressively mix. Pour into the prepared pan and smooth the top with an offset spatula or spoon. Break up the cookies and press them into the batter all over the top then sprinkle over the remaining chips on top.
Bake the brownies. Times for baking will vary depending on your oven and how chewy or cakey you want your brownies and the recommended bake times on the box from the manufacturer. In my convection oven 18 minutes was for super fudgy brownies, 21 minutes for chewy but not too dense brownies (how I like them) and 27 minutes for cakey. Your times will vary if using a regular oven and/or larger or smaller pans. Most boxes have baking times listed on them so always check them for the sized pan you’re using. Also note that glass and nonstick pans will bake faster than aluminum, stainless or earthenware pans.
Cool, cut and enjoy!

Notes

Sunflower seed, almond or cashew butter should work as well if you don’t want to use peanut butter but these are PB brownies after all.
Use a good dense vegan stick or block style butter. Tub butters have more water but if it’s all you have it will work as well. I have not tested coconut oil and plain oil will work as well but vegan butter worked the best in my tests.
If using a smaller sized mix (on the 16 oz size end) reduce the amount of water by a few tablespoons then add it back in if the mix seems too dry. You can always add but you can’t take it away.
Most brownie mixes I’ve tried have worked well with this method. I usually buy Duncan Hines mixes but store brand mixes have worked well and others. I tested quite a few and all with good results.