Blondies with Peanut Butter and Marshmallow

by Jessica Selensky on May 16, 2024 0 comments

These Blondies with Peanut Butter and Marshmallow are a nostalgic treat and also easy to make. The peanut butter, cookie and marshmallow combination is delicious.

Sliced Blondies with Peanut Butter and Marshmallow on a platter.

These bars were gone the same day I made them. They are THAT good!

You might want to consider making two batches instead of one so that you don’t have to run out.

If you’re a peanut butter lover like myself, this recipe is perfect for you.

These Peanut Butter Blondies are the perfect way to enjoy this magical combo of peanut butter and marshmallow. It reminds me of enjoying a fluffernutter as a kid!

So grab your peanut butter, marshmallows and the other ingredients outlined below. We’ve got Fluffernutter-Inspired Blondies to make!

Main Ingredients

Peanut Butter and Marshmallow Blondie ingredients measured out in bowls.

What Mix-Ins can I Add to these Fluffernutter Bars?

There are so many delicious mix-ins that you can add to this recipe.

My favorites are what you see in the images: Peanut Butter, Nutter Butter Cookies and Marshmallows.

However, you can mix it up by using Marshmallow Fluff swirled on top instead of marshmallows.

In the batter, you can mix in Peanut Butter Chips. You can put them on top of the batter as well. I have bought Peanut Butter Baking Chips at Trader Joe’s and they work great!

As always, you can get creative! What would you add to these Fluffernutter-Inspired Blondies?

How to Make Blondies with Peanut Butter and Marshmallow

Preheat the oven to 350 degrees F
Add the eggs, brown sugar, butter and vanilla extract to a bowl
Mix until combined
Add in the creamy peanut butter and mix until combined
Fold in the flour and mix until just combined
Transfer to a square 8×8 baking pan that has been lined with parchment paper or greased
Spread out the batter in an even layer
Swirl in about 2-3 tbsp of creamy peanut butter on top (you could also swirl in marshmallow fluff here)
Press 4-5 nutter butter cookies gently into the top of the blondie batter
Bake in the oven for 28-30 minutes, then remove the pan from the oven
Add the large marshmallow halves (or mini marshmallows) on top. Gently press into the bars
Turn the oven on Broil (High)
Put back into the oven and broil on High for about 2 minutes or until the marshmallows are perfectly toasted
Remove from the oven
Let cool completely before slicing
Slice and enjoy!

Wet ingredients in a bowl to make the blondie batter. — Add the wet ingredients to a large mixing bowl

Making the blondie batter with peanut butter. — Add the wet ingredients to a large mixing bowl

Frequently Asked Questions

Can I use mini marshmallows?

Yes! You can top the Peanut Butter Blondies with Mini Marshmallows instead of the larger ones. You won’t need to cut them in half since they are much smaller.

NOTE: They may toast more quickly in the oven so keep an eye on it when broiling.

What kind of peanut butter should I use?

I highly recommend using a creamy, all natural peanut butter as it is looser texture than a more processed peanut butter.

TIP: Heat in the microwave at 15 second intervals to loosen up the peanut butter before adding it to the batter.

How do I know the Blondies with Peanut Butter and Marshmallow Fluff are done baking?

A toothpick should come out of the center clean (with maybe a few crumbs).

Do I have to let the peanut butter blondies cool before slicing?

Yes! Let the blondies cool completely before slicing as this will allow for a clean cut.

How do I store the bars?

Store in an airtight container at room temperature for up to 3 days or in the fridge for 5 days.

You can also freeze the bars for up to 1 month in a freezer-safe container. When ready to eat, reheat in the microwave for 30-45 seconds or until warm.