Peanut Butter Marshmallow Cereal Bars

As soon as August hits every year, I start thinking/wishing about fall. I know some people are like, NO! But, you guys know me, I love fall. Also, is it Halloween yet?

Too soon?

I made these Marshmallow Peanut Butter Cereal Bars a couple of months ago actually and have been holding off to post them as they just seemed like a good August recipe. I guess I’m thinking of them as the perfect little after-school treat or to stick in lunch boxes (if your schools allow peanuts, of course…) for the kiddos! But, I’d be totally lying if I said that these are just for the kids because I found them to be pretty darn addictive myself!

Peanut Butter Marshmallow Cereal Bars

Now, I wouldn’t go as far as to say that these cereal bars are healthy considering they contain a bunch of butter and marshmallows, but hey, the cereal is made with whole grains and peanut butter has some good protein! So, they are “better-ish”, right?!




Let’s go with YES!

For these cereal bars, I used plain whole grain Cheerios. You can use something different if you prefer, but knowing I was adding marshmallows, I didn’t want them to be too sweet by using a sweetened cereal. Also consider your peanut butter. You can either use regular ol’ peanut butter which has added sugar or natural peanut butter. I’ve used both and it’s really up to you. My kiddos seem to prefer them with regular peanut butter so that is what I use, but you can cut down on the sugar by using natural peanut butter if desired!

I left these plain, but you can also mix in chopped peanuts, mini marshmallows, or other candies if you want to take them up a notch!

Peanut Butter Marshmallow Cereal Bars

Peanut Butter Marshmallow Cereal Bars
Yield: 10-12 bars or squares

Peanut Butter Marshmallow Cereal Bars

Prep Time 20 minutes
Total Time 20 minutes

A fun twist on rice cereal treats made with Cheerios and peanut butter! A perfect treat for kids!


  • 4 tablespoons unsalted butter
  • 5 cups mini marshmallows
  • 1/2 cup creamy peanut butter
  • 1 teaspoon vanilla extract
  • 5 cups plain toasted oats cereal (like Cheerios)


  1. Line an 9x13 baking dish with parchment paper and set aside.
  2. In a large pot over medium high heat, melt the butter and marshmallows until smooth and completely melted. Stir in the peanut butter and vanilla extract until combined. Add the cereal and stir until it is fully coated in the marshmallow mixture.
  3. Transfer the mixture to the baking dish. Use greased hands or a greased spatula to spread and press the mixture into an even layer in the dish. Let stand for about 1 hour. Cut into squares or bars or store in an airtight container for at least 15 minutes.

Nutrition Information:



Serving Size:

1 piece (when cut into 10)

Amount Per Serving: Calories: 218Total Fat: 12gSaturated Fat: 4gTrans Fat: 0gUnsaturated Fat: 6gCholesterol: 10mgSodium: 82mgCarbohydrates: 25gFiber: 3gSugar: 9.8gProtein: 5g

Peanut Butter Marshmallow Cereal Bars