No-Bake Peanut Butter Marshmallow Cereal Bars

These bars are a hybrid of some of my favorite bars.

No-bake, ChewyGooey, Caramely, with Peanut Butter, Special K, Cereal, Marshmallows.

No-Bake Peanut Butter Marshmallow Cereal Bars - Easy 5-Minute Recipe at

And they’re so good. And so easy.

Ever since I made the Chewy Peanut Butter and Chocolate Cereal Bars, I’ve been thinking about how to remake them in a slightly new way.

No-Bake Peanut Butter Marshmallow Cereal Bars - Easy 5-Minute Recipe at

These bars are based heavily on those, but instead of using Rice Krispies, I used Special K. You could also use Corn Flakes, Frosted Flakes, Rice Krispies, or a similar vegan or gluten-free cereal.

Instead of topping them with chocolate-peanut butter swirls, I stirred in marshmallows. I love marshmallows in bars because they lend so much gooey-and-chewy texture.

Plus, marshmallows are more well-behaved in the Caribbean heat and don’t melt everywhere like chocolate.

No-Bake Peanut Butter Marshmallow Cereal Bars - Easy 5-Minute Recipe at

No-bake bars like these are always nice so you don’t have to heat up your house, especially this time of year.

And they’re made in one bowl in the microwave, and take less than 5 minutes to stir together. Usually it’s the fast and easy recipes people seem to make anyway, and you can add this one to the Fast and Easy list.

No-Bake Peanut Butter Marshmallow Cereal Bars - Easy 5-Minute Recipe at

There’s no butter in the recipe, but you’d never guess it because they’re exceedingly buttery-tasting and rich.

The microwave-made sauce drenches the cereal in a sweet, brown sugary, caramel-vanilla, peanut buttery syrup and holds the bars together.

No-Bake Peanut Butter Marshmallow Cereal Bars - Easy 5-Minute Recipe at

I love bars that I can really sink my teeth into, and these deliver.

They’re dense, wonderfully soft, with tons of chewiness and texture from the cereal and marshmallows.

No-Bake Peanut Butter Marshmallow Cereal Bars - Easy 5-Minute Recipe at

Peanut butter has a way of making everything taste so good and decadent.

Even Special K.

No-Bake Peanut Butter Marshmallow Cereal Bars - Easy 5-Minute Recipe at

No-Bake Peanut Butter Marshmallow Cereal Bars

These fast, easy, no-bake bars are a hybrid of some of my favorite bars, which include peanut butter, marshmallows, cereal and are held together with a brown sugar-caramel sauce that’s made in the micro in 1 bowl. They’re dense, wonderfully soft, with plenty of chewiness and texture and you can really sink your teeth into them. There’s no butter in the recipe, but you won’t miss it because the bars are rich and very buttery tasting.

Did you make this recipe?


1 heaping cup creamy peanut butter (use Jif, Skippy, or similar; do not use natural or homemade peanut butter)
1/2 cup light corn syrup (light colored, not lite)
1/2 cup granulated sugar
1/4 cup light brown sugar, packed
1 tablespoon vanilla extract
3 1/2 cups Special K cereal (Corn Flakes may be subsituted, or use about 3 cups Rice Krispies cereal)
about 5 ounces marshmallows (half of one standard bag; I used large but mini are ideal)


  1. Line an 8-inch square pan with aluminum foil leaving overhang, spray with cooking spray; set aside.
  2. In a large microwave-safe bowl, combine 1 heaping cup peanut butter, corn syrup, sugars, and heat on high power for 1 minute to melt.
  3. Stop to stir. Mixture will be on the granular side, this is okay.
  4. Return bowl to microwave and heat for 1 more minute on high power.
  5. Stir in the vanilla.
  6. Stir in the cereal and marshmallows. The marshmallows will melt to some extent, but not fully.
  7. Turn mixture out into prepared pan, packing it down somewhat firmly with a spatula, and smooth the top.
  8. Cover pan with a sheet of foil (to prevent fridge smells), and place pan in fridge to set up for about 2 hours or until set, before lifting out with foil overhang, slicing, and serving.
  9. Bars will keep airtight at room temperature for up to 1 week, in the refrigerator for up to 2 weeks, or in the freezer for up to 6 months.

Adapted from Chewy Peanut Butter and Chocolate Cereal Bars

Recipe from Averie Cooks. All images and content are copyright protected. Please do not use my images without prior permission. If you want to republish this recipe, please re-write the recipe in your own words, or simply link back to this post for the recipe. Thank you.

Only Eats

Related Recipes:

Chewy Peanut Butter and Chocolate Cereal Bars (no-bake, vegan, GF)

Chewy Peanut Butter and Chocolate Cereal Bars (vegan, gluten-free) - Recipe at

Peanut Chewy Payday Bars (almost no-bake)

Caramel and Chocolate Gooey Bars

Double Chocolate Caramel Corn & Cocoa Rice Krispies Candy Bars

Nutella and Peanut Butter Graham Bars with Chocolate Frosting

Browned Butter Rice Krispies Treats – The best RKTs I have ever had. Double the butter and it’s browned, for great flavor and soft, buttery, chewy bars

Special K Bars

No-Bake Nutter Butter Special K Bars

Peanut Butter Caramel Twix Bars (almost no-bake)

Peanut Butter Chocolate Chunk Cookie Bars

Nutella-Swirled Peanut Butter Chip Blondies

Nutella-Swirled Peanut Butter Chip Blondies - Easy One-Bowl No-Mixer Recipe at

Biscoff Marshmallow Chocolate Bars

Biscoff Marshmallow Chocolate Bars from

Marshmallow Caramel Oreo Cookie S’Mores Bars

Marshmallow Caramel Oreo Cookie S’Mores Bars

 Thanks for the entries in the 3-Piece Baking Set and Gluten-Free Dough Giveaway and the $100 My Sweet Muffin Giveaway

What’s your favorite no-bake or fast and easy dessert?

67 comments on “No-Bake Peanut Butter Marshmallow Cereal Bars”

  1. These look so amazing! I love that you added the marshmallows. That totally takes these into over-the-top awesomeness! :)

  2. I love bar like this. They are honestly the one thing I eat by my self because I am too ashamed to admit I still love them at 21… Eh.. more for me.
    PB and marshmallow? Heaven in a portable snack!

  3. I love a gooey bar–and no bake cereal bars and cheesecake taste good any time of year, but especially in the summer. My most frequently made fast summer dessert is throwing frozen stuff into the vita for instant sorbets or ice cream. Hmmm….I think a little coconut milk ice cream or banana soft serve might be good on top of these too!

  4. Gawd, I love reading the phrase “do not use natural or homemade peanut butter.”

    Almost as much as “does not contain raisins.”

    • There are times for natural PB and then there are times for Jif, Skippy, or Peter Pan. They are like glue and work WONDERS here whereas natural is like a soft oil slick and not really ideal :)

  5. Something very similar to these is actually on the menu for this morning. I love peanut butter no bake treats like this and adding marshmallows was a great idea!

  6. Cereal bars like this are the best! I’m so happy you made these – they sound delicious!

  7. I love this spin on the special K-Bar!! Special K- BArs are my family favorite and these look like they could compete! WOW oh wow! I love all that gooeyness on top and the peanut butter. YUM!!

    • I know you have a recipe for them, too! My Special K bar recipe is from 2010 so I figured it could use a little updating. Then again, it was my grandma’s recipe from like 1960 and has served us very well :)

  8. Oh goodness! I have all of the ingredients to make these right now. These are going to be pretty dangerous to have around, but I’m betting they’re totally worth it! thank you for sharing :)

  9. I love trying new no bake bars. What a good idea to use Special K cereal!

  10. no bake bars are my favorite to make. So easy to come together too!

  11. You had me at “peanut butter”, “marshmallow” and “no bake”. In other words, the entire thing! Delicious!

  12. These look quite delicious too me. And no baking – perfect!

  13. Since these bars are made with Special K that means they’re healthy, right? So it’s okay to enjoy several… :D

    I love your hybrid creations!

  14. I love how much you love peanut butter. And no bake – even better! Thanks for these!

  15. So mouth watering, Averie! I love how you take those extra steps like cutting squares of parchment paper for each bar :)
    Lately I’ve been making an easy dessert in the food processor of banana ice cream with frozen banana, peanut butter, bits of chopped TJ’s dark chocolate, and some vanilla extract.

    • I do it b/c it looks nice but really, b/c things melt here in the heat and I don’t want the gooey stuff melting and sticking to my wood table. In San Diego it’s not an issue but here in Aruba, hot, humid, sticky city :) But thanks for noticing (b/c it’s a total pain and does take time! lol) Your easy dessert sounds wonderful!

  16. Ahhh Averie! I love that you combined 3 of my favorite things- peanut butter, marshmallows and convenience! Lol ;) I’m in love with no-bake bars and they’re especially good when they’re dense and chewy like these. I’ve been wanting to experiment with no-bake bars lately….just haven’t gotten around with it. I’m thinking something with oats/oat flour and almond butter as the main components. Maybe a little coconut oil too ;) I’ll let you know if I get a chance to make these! Happy Sunday!

  17. These look great and I love how versatile they can be just by mixing up the type of cereal you use! Yum!

  18. I need more bars in my life. And marshmallows. And peanut butter.

    I guess I need these, huh?

  19. Some of my best creations come from experimenting with my old “hybrid” recipes.
    So, yeah, keep going. LOL

  20. Averie I am loving these! I am all about no-baking lately because quite frankly – I don’t want to turn on my oven! When we were at the lake, there were SO many of us that I just decided to make no-bake pies instead of cake for Kevin’s birthday. The house was already so hot from everyone inside it! Anyway, these bars are just glorious. I love marshmallow and PB together. These look like a texture lovers dream!

    • Nobake pies sound great. You are the queen of all those anyway with so many on your site I’ve always wanted to try! And PB + brown sugar (which turns to caramel in the micro) + m’mallows is so good. And they ARE indeed a texture lover’s dream!

  21. I can’t believe there’s no butter in these…I would never have guessed! I love how ooey gooey they are! These could be dangerous around the house… but that’s just how I live– on the edge of danger… with lots of sugar!

  22. Mmm! I can almost taste the gooey sweetness of these bars! I need to make bars like this more often. I forget how good they are! (And how versatile other cereal is, besides rice krispies!)

  23. Yes love this. I would never have thought of this. Might try them with Rice Krispies. Thanks for a great recipe :)

  24. These sound wonderful, Averie! No bake desserts are great this time of year!

  25. The chewiness and texture of these sounds amazing!

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