Toasted Marshmallow Peanut Butter Bars

What is it about the end of summer and toasting marshmallows? I don’t know about you, but as the weather starts to cool down, I have a desire to pile puffy marshmallows on a stick and roast them on an open campfire. It’s too bad that campfires are banned in our area due to the high risk of forest fires, but I can still get my fix by making these delicious peanut butter bars that are topped with a marshmallow meringue. Once I use my trusty torch on them, it’s the next best thing to sitting around a campfire!

Don’t be fearful of making a meringue frosting or using a propane torch…both are easy once you get the hang of them. Just follow the directions below and you should be golden!

Toasted Marshmallow Peanut Butter Bars
Toasted Marshmallow Peanut Butter Bars

A lot of people buy the small kitchen torches. I went for the industrial model (what the welders use! Ha!) at Home Depot. I found that the small torches ran out of propane too quickly and are very expensive. The one I bought was about $20 for the tank and torch head and I will get years of use from one tank.

If torching makes you nervous (it’s actually kinda fun!), it’s okay to leave the bars untorched.

Toasted Marshmallow Peanut Butter Bars

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Toasted Marshmallow Peanut Butter Bars

Makes: 16 squares

Prep Time: 30 minutes

Bake Time: 40 minutes

Total Time: 1 hour & 10 minutes


Peanut Butter Cookies Bars:

  • 1 & 2/3 (210g) cup all purpose flour
  • 1 tbsp cornstarch
  • 1/2 cup old fashioned rolled oats, lightly ground in a food processor
  • 1/2 tsp baking soda
  • 1/2 tsp salt
  • 3/4 cup creamy peanut butter (like Jif or Skippy)
  • 1/2 cup unsalted butter, room temp
  • 1/2 cup light brown sugar, packed
  • 1/4 cup granulated sugar
  • 1 large egg
  • 1 tsp vanilla extract

Marshmallow Meringue:

  • 2 large egg whites
  • 1/2 cup granulated sugar
  • 1/4 tsp cream of tartar
  • 1/2 tsp vanilla extract


Peanut Butter Cookies Bars:

Preheat the oven to 350°F and grease an 8×8 baking dish. Line the bottom and sides with a sheet of parchment paper and allow it to hang over the edges. This will make it easy to lift out the bars once they’ve baked and cooled.

Whisk together the flour, cornstarch, oats, baking soda, and salt and set aside. In a large bowl, mix together the butter and peanut butter until smooth. It’s best to use a hand mixer or a stand mixer fitted with the paddle attachment.

Mix in the sugars until combined, followed by the egg and vanilla.Lastly, dump in the dry ingredients and mix to combine. Press the dough into the baking pan and bake for 25-30 minutes or until the edges are golden brown. Allow the bars to cool completely, still in the pan, then make the marshmallow meringue topping.

Marshmallow Meringue:

Add the egg whites and sugar to the bowl of a stand mixer. If you don’t have a stand mixer, make sure to use a heat safe bowl. Place the bowl over a pot of simmering water (filled about 1/2-1/3 of the way full). Make sure it doesn’t touch the water and don’t let the water come to a boil. Whisk occasionally until the sugar is completely dissolved (about 10 minutes). To test, rub some of the mixture between your fingers. If you still feel sugar granules, keep it over the heat until you can no longer feel those granules. Transfer the bowl to the stand mixer with the whisk attachment and whip on high speed. As it turns white and opaque, add in the cream of tartar and vanilla. Keep whisking until it’s thick and glossy. To test, dunk the whisk into the bowl and pull it out. When you turn it right side up, the meringue should still stand straight.

Spread the meringue onto the cooled cookie bars. Use a kitchen torch to lightly toast the top (if you don’t have one, you can omit this step). Slice and enjoy!

Recipe by Butternut Bakery


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