Peanut Butter Cheerio Bars with M&Ms are insanely delicious cereal treats loaded with marshmallows and peanut butter and topped with M&Ms, a peanut buttery drizzle, and salty roasted peanuts. Perfect lunch box treat or after school snack.
This post was updated 115/22 with new ingredients. If you’re looking for the cereal treat recipe with candy corn, click here.
Rice Krispie treats aren't the only cereal bars in town.
Cheerio Peanut Butter Bars are ridiculously yummy no bake treats you can make on the stovetop or in the microwave with butter, creamy peanut butter, tons of marshmallows, and Cheerios.
You could stop right there and have very delicious 4 ingredient peanut butter Cheerio bars. But I suggest you keep going.
Add M&Ms, a drizzle of melted peanut butter chips, and salty roasted peanuts to turn simple Peanut Butter Cheerio no bake bars into an extra-special sweet treat.
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Why You'll Love This Recipe
Delicious and fun alternative to Rice Krispies treats
Easy recipe for no bake peanut butter Cheerio bars
Salty sweet cereal bar treats kids and grown ups alike will devour
Super gooey peanut butter Cheerio treats you can load up with all your favorite things
Easy no bake recipe with simple ingredients.
Plain Cheerios. I like using the plain, original Cheerios because the marshmallow mixture is sweet. For sweeter bars, try Honey Nut Cheerios, Apple Cinnamon Cheerios, or any other flavor of cereal you love.
Creamy peanut butter. You can use smooth or crunchy peanut butter. Either will work.
Peanut butter chips. The melted peanut butter chip drizzle on top adds even more peanut butter flavor. If you want, you can even toss some into the marshmallow peanut butter mixture with the cereal, but that's totally optional.
Marshmallows. You can use mini or regular marshmallows, the large ones will just take a little longer to melt. For the gooeyest bars, use fresh marshmallows.
Peanuts. Salted roasted peanuts add crunch and salt. You can use almonds, walnuts, hazelnuts, pistachios — any nut will work.
M&Ms. I use plain M&Ms, but you can use your favorite flavor of M&Ms -- peanut, peanut butter, dark chocolate, minis ...
Salt. A sprinkle of sea salt adds a salty relief against the sweet, and a crunchy texture.
How to Make Peanut Butter Cheerio Bars
1. Prepare the pan
Grease an 8x8, 9x9, or similar-sized baking dish with butter or spray it with cooking spray.
You can also line the pan with parchment paper or aluminum foil sprayed with cooking spray so you can lift the entire slab of bars out of the pan for easy cutting.
2. Melt butter, peanut butter, and marshmallows
In a large pot or Dutch oven on low heat, melt the butter and peanut butter together.
Add the marshmallows and stir until melted.
Remove the pot from the heat and stir in the vanilla.
3. Add the Cheerios to the marshmallow mixture.
In the same pot, add the Cheerios and stir until well coated with the marshmallow peanut butter mixture.
4. Pour the cereal mixture into the the prepared baking dish.
Pour or spoon the Cheerio mixture into the prepared pan and firmly press it down with a silicone spatula.
5. Top with M&Ms, peanut butter drizzle, and chopped peanuts.
Gently press the M&Ms into the top of the bars.
In a small microwave-safe bowl, melt ¾ cup peanut butter chips and 2 teaspoons butter in 30 second intervals, stirring in between, until the chips are melted. Add a little bit of water and stir until it is smooth, creamy, and the perfect drizzling consistency.
Drizzle the melted peanut butter chips over the Cheerio bars in a very Jackson Pollock sort of way.
Immediately sprinkle chopped roasted peanuts in an even layer over the peanut butter drizzle before it sets. If desired, add a sprinkle of coarse or flaky sea salt.
Place in the refrigerator to set for about 2 hours.
6. Slice, serve, and enjoy!
The best way to cleanly cut the bars is to cut them while they're still chilled. Remove the whole slab from the pan, place it on a cutting board, and use a very sharp knife to cut the bars into squares.
How to Make Peanut Butter Cheerio Bars in the Microwave
You can easily make Peanut Butter Cheerio bars in the microwave, providing you have a VERY LARGE bowl that's microwave-safe.
Prepare the pan as directed in step 1 above.
Place the butter, peanut butter, and marshmallows in a large microwave-safe bowl. Microwave on high for 2-3 minutes, stopping to stir every minute (the marshmallows get really big and puffy!), until everything is melted, creamy, and smooth.
Immediately pour the Cheerios into the bowl and stir until all the Cheerios are completely coated in peanut butter marshmallow goo.
Press mixture into the prepared pan and proceed with step 5 above.
Storage & Freezing
Store Peanut Butter Cheerio Bars in an airtight container at room temperature for 3-4 days or in the fridge for about a week.
Can I freeze marshmallow cereal treats?
Yes! Just be sure they are completely cooled. Pack them in a freezer safe container between rows of wax paper or individually wrapped in plastic in a freezer bag. Thaw at room temperature.
Want to jazz up your peanut butter Cheerio bars even more? Try changing up the flavors!
Cereal. Instead of regular Cheerios, try a different flavor of Cheerios, Corn or Rice Chex, Special K, or Kix -- or flavored cereal like Cocoa Puffs, Golden Grahams, Peanut Butter Crunch, or Reese's Puffs.
Chocolate chips. Sprinkle chocolate chips on top instead of -- or in addition to -- the M&Ms.
Peanut butter chips. Stir in ½ cup of peanut butter chips with the Cheerios. They will melt and add even more peanut buttery flavor to your treats.
Nuts, seeds, fruit, pretzels, cookies. Stir in ½ cup of chopped nuts, sunflower seeds, pepitas, shredded coconut with the cereal, dried fruit, crushed pretzels or cookies.
Spices. Add a teaspoon of cinnamon, pumpkin spice, Chinese 5 spice, or your favorite warm spices or spice blends.
Extracts. Instead of vanilla extract, try almond, maple, or coconut extract.
Use low heat to melt the butter, peanut butter, and marshmallows. If you warm them over higher heat, they can burn.
Butter or grease the baking pan or line it with parchment paper so you can easily remove the bars from the pan.
Use a very large pot so you have plenty of room to stir the Cheerios and coat them in the yummy peanut butter marshmallow mixture.
For thick bars, use an 8 or 9 inch pan -- or similarly sized. A 9x13 pan also works, the bars will just be thinner.
Use a rubber spatula to press the sticky cereal mixture into the pan.
If cereal treats have too much butter, they won't hold together. Same goes for too much peanut butter.
It takes 1-2 hours for cereal treats to harden. You can speed up the process by placing them in the refrigerator.
No. Keep the pan uncovered while the treats are cooling. Once they are completely cooled, cover the pan with plastic wrap or aluminum foil or store the bars in an airtight container or wrapped in plastic warp.
A silicone spatula and spoonula set are so handy for working with sticky things like melted marshmallows.
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Peanut Butter Cheerio Bars
- 4 tablespoons butter
- ⅔ cup creamy peanut butter
- 8 cups marshmallows
- 1 teaspoon vanilla extract
- 6 cups Cheerios
- ½ cup M&Ms
- ¾ cup peanut butter baking chips
- 2 teaspoons butter
- 1-2 tablespoons water
- ¼ cup roughly chopped roasted peanuts
- sea salt
Make the Peanut Butter Cheerio Bars
- Prepare an 8x8, 9x9 or equivalent sized pan with parchment paper or aluminum foil sprayed with nonstick cooking spray. You can also use a 9x 13 pan for thinner bars.
- Melt butter and peanut butter together in a large pot or Dutch oven over low heat.
- Add the marshmallows and stir until melted. Remove from heat and stir in the vanilla.
- Pour the Cheerios into the pot and stir until the Cheerios are completely coated in the marshmallow mixture.
- Pat the mixture into the prepared pan with a silicone spatula.
Add the Toppings
- Gently press ½ cup M&Ms onto the top of the peanut butter Cheerio bars.
- Place ¾ cup peanut butter chips and 2 teaspoons butter in a small microwave-safe bowl. Heat in 30-second increments, stirring in between, until melted. Add small amounts of warm water until the mixture is smooth, creamy, and a drizzling consistency.
- Drizzle the melted peanut butter chips over the peanut butter Cheerio bars. Sprinkle with chopped peanuts and top with flaky sea salt, if desired.
- Let the bars set for 1-2 hours to firm up. You can place them in the refrigerator to speed up the process.