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Peanut Butter Banana Brownies

Welcome to the August 2nd, 2015 edition of Sunday Scratchups, your weekly recipe from scratch (or in this case, semi-scratch) around grocery sales and affordable ingredients. This week’s mystery sale ingredients: Peanut butter and brownie mix! So you know how a lot of my Sunday Scratchups recipes are healthier and/or allergy friendly? Well...

This ain't one of them.

Peanut Butter Banana Brownies are straight up doctored-box-mix comfort food, coming out more like a chocolate banana bread than a gooey brownie. The peanut butter and banana add a little something to the basic box mix, though, and these taste at least slightly closer to homemade than the original box recipe.

What are we doing here...?

peanut butter brownie mix and bananas

Earlier this week, I picked up a jar of Smucker's natural peanut butter for $1.49 (reallllly good, by the way) and a box of brownie mix for $.25. I also had a bunch of overripe bananas left here from when family was in town earlier this week, so decided to substitute a couple of those for the oil originally called for in the box recipe, and to cook it in a smaller pan in order to create a thicker more cake-like brownie banana bread. And so we have...

Peanut Butter Banana Brownies!

gooey brownie

Ingredients

1 box brownie mix
2 overripe bananas
2 eggs
¼ cup water
¼ cup chopped walnuts (optional)
¼ cup creamy natural peanut butter
¼ cup semi-sweet chocolate chips (optional)

Directions

Mix brownie mix, eggs, and water in large bowl. Slice bananas into coins, add to bowl, and whisk in until fairly smooth. Stir in walnuts. Grease an 11x7 glass pan and pour in batter. Drizzle on peanut butter, then swirl with a butter knife. (Note: If you aren't using the goopier natural peanut butter you'll need to warm it in the microwave for 15-20 seconds to liquify a bit before pouring on brownies.)

plate of peanut butter banana brownies

Scatter chocolate chips on top. Bake at 350 degrees for 45 minutes, or until a knife inserted in the center pulls out clean.

Yum yum comfort food

slice of peanut butter banana brownie

See? How could that be bad! You can even pretend it's healthy with the bananas and natural peanut butter and all, and I sure won't tell anyone. 😉 These are rich, chocolatey, and satisfying, and the peanut butter chocolate chip topping perfectly complements the brownie & bananas combination.

Peanut Butter Banana Brownies, easy print version

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4 from 2 votes

Peanut Butter Banana Brownies

Doctor up a boxed brownie mix into something a little more special!
Course Dessert
Total Time 55 minutes

Ingredients

  • 1 box brownie mix
  • 2 overripe bananas
  • 2 eggs
  • ¼ cup water
  • ¼ cup chopped walnuts optional
  • ¼ cup creamy natural peanut butter
  • ¼ cup semi-sweet chocolate chips optional

Instructions

  • Mix brownie mix, eggs, and water in large bowl.
  • Slice bananas into coins, add to bowl, and whisk in until fairly smooth.
  • Stir in walnuts.
  • Grease an 11x7 glass pan and pour in batter.
  • Drizzle on peanut butter, then swirl with a butter knife.
  • (Note: If you aren't using the goopier natural peanut butter you'll need to warm it in the microwave for 15-20 seconds to liquify a bit before pouring on brownies.)
  • Scatter chocolate chips on top.
  • Bake at 350 degrees for 45 minutes, or until a knife inserted in the center pulls out clean.
Recipe Rating




Missy

Sunday 9th of November 2025

In an 11 x 17 pan, these are very thin and only needed to bake for about 25 minutes. I think a 9 x 13 might be better. I followed the recipe exactly and didn’t love the flavor but I can see how others might.

rachel

Sunday 9th of November 2025

Perhaps the issue here is that the recipe calls for an * 11x7 * pan, not 11x17. Happy Baking! 🙂

John

Saturday 8th of November 2025

Used the Reese's Peanut Brownie mix and just added bananas and come coconut I had in the freezer... fantastic.

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Friday 4th of January 2019

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