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Peanut Butter Rice Krispie Treats Recipe

This is not only a peanut butter Rice Krispie treats recipe. It’s a peanut butter Rice Krispie treats recipe made with homemade marshmallows and rainbow chip crunch sprinkles.

Why would I do such a thing?

Well, the short answer is that the challenge for last week’s reddit 52 week baking challenge was gelatin. And while I really did entertain the idea of making an avocado aspic, I decided it would be better to make the homemade marshmallows recipe from King Arthur baking.

peanut butter rice krispie treats with rainbow chips.
a blue plate filled with squares of homemade marshmallows.

And once I had a pan full of marshmallows, I needed to do something with them.

My first go was a recipe for s’mores cookies, but they need a little more work. (Edit to add: those s’mores cookies turned into these s’mores bars.)

Then I realized that this week’s reddit challenge (Week 33) was “picnic.” And what could be better for a summer picnic than an easy-made dessert that doesn’t require turning on the oven. These peanut butter Rice Krispie treats are sturdy enough to get bounced around in a picnic basket. And they won’t melt in the summer heat or risk giving everyone food poisoning. That’s a pretty important thing when you’re an infectious disease doctor.

Kiddo, of course, wanted to add color, so we tossed in some rainbow chips. I like these sprinkles because they’re a bit larger (~5mm) and don’t melt as quickly as regular sprinkles.

a measuring cup filled with rainbow chip sprinkles.

Tips and tricks for these peanut butter Rice Krispie treats

This peanut butter Rice Krispies recipe is adapted from the recipe on the box with the addition of 1/2 cup of peanut butter and those rainbow sprinkles. There are some times that you can’t improve on the recipe on the box, and you shouldn’t even try.

Homemade marshmallows have a softer, smoother texture, and you can vary the flavor any way you desire. So I would encourage you to make your own marshmallows at least once, but feel free to use a bag of store-bought marshmallows in this recipe.

homemade marshmallows being added to the pan of melted peanut butter and butter
homemade marshmallows starting to melt in a pan ofmelted peanut butter and butter

There is nothing complicated here. Just be sure to keep the pan on low, and stir to prevent everything from sticking to the bottom.

FAQs about this peanut butter Rice Krispie treats recipe

Should it be Krispy or Krispie?

Right? It’s a made up word, so I think anything goes. Kellogg’s calls them Rice Krispies Treats (TM), but I think that’s hard to say.

Can I make this in the microwave?

Sure. Here are the original instructions. Just add peanut butter.

Why don’t you use natural peanut butter in baking?

You can use natural peanut butter in most baking that calls for peanut butter, but you will often get a different texture. You also may need to adjust the salt and sweetness to your liking.

Can I substitute chocolate chips for the sprinkles?

Yes, you’ll just want to work as quickly as possible to incorporate them into the mixture, just like with the sprinkles.

How should I store peanut butter Rice Krispie treats?

You’ll want to keep them at room temperature, either in the pan and covered tightly with plastic wrap, or in an air tight container with a piece of wax paper in between layers.

Why do you have a picture of your kitchen sink at the end of this post?

Someone on Facebook recently shared a request for recipe posts to show the mess that has to be cleaned up after you make the recipe. I’m guessing the post was intended to be a joke, but I think it’s a great idea. So many recipes underestimate how much time it takes us from start to finish, and none account for the time it takes to clean up!

a pyrex baking dish full of this peanut butter rice krispie treats recipe

Peanut butter Rice Krispie treats with rainbow chips

Prep Time 15 minutes
Cook Time 5 minutes
Cooling time 30 minutes
Total Time 50 minutes
Servings 24 bars
Calories 122kcal
Author uglyducklingbakery


  • 6 cups Rice Krispies cereal
  • ½ cup smooth peanut butter not all-natural
  • 3 tbsp (43g/1.5oz) unsalted butter plus more greasing the pan
  • 10 oz marshmallows, homemade or store-bought
  • ½ cup rainbow chips or sprinkles


  • Butter a 9"x13" Pyrex or other baking pan.
  • Measure out cereal into a large, heat-proof bowl.
    6 cups Rice Krispies cereal
  • In a medium to large sized pot, melt the peanut butter and butter together over low heat.
    1/2 cup smooth peanut butter, 3 tbsp (43g/1.5oz) unsalted butter
  • Add the marshmallows and stir until melted.
    10 oz marshmallows, homemade or store-bought
  • Quickly stir the peanut butter-marshmallow mixture into the cereal.
  • Once it has been mostly mixed, add the rainbow chips and quickly mix.
    1/2 cup rainbow chips or sprinkles
  • Transfer the mixture into the buttered pan, and use the spatula or your hands to spread the mixture evenly into the pan, pushing down on it gently.
  • Let it cool for at least 30 minutes before cutting.
  • Store at room temperature, covered with plastic wrap, for one week.


  • It is important to work quickly to combine the peanut butter-marshmallow mixture to the cereal before it cools.
  • The rainbow chips are added only at the very end to prevent them from melting too much.


Calories: 122kcal | Carbohydrates: 20g | Protein: 2g | Fat: 4g | Saturated Fat: 2g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 2g | Trans Fat: 1g | Cholesterol: 4mg | Sodium: 71mg | Potassium: 45mg | Fiber: 1g | Sugar: 11g | Vitamin A: 509IU | Vitamin C: 4mg | Calcium: 3mg | Iron: 2mg

What’s next?

If you make this peanut butter Rice Krispie treats recipe, want to reminisce about your childhood, or have another favorite recipe on the box, please leave a comment or rating here. Or share a pic with me on Instagram!

Check out other uglyduckling bakery easy cookie recipes, like these Nutella blondies or salted caramel chip chocolate cookies.

Or, if you are a lover of peanut butter, you should check out:
Peanut butter chocolate chip cookies
Peanut butter chocolate drip cake
Peanut butter waffles
Peanut sauce for a tofu noodle bowl
The peanut butter manhattan

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Previous challenges:
Week 1: New Year new recipe – blueberry galette
Week 2: seasonal – Smitten Kitchen’s grapefruit pound cake
Week 3: Great British Bake Off – Kate’s sticky toffee apple caramel cake
Week 4: Australia – sausage rolls
Week 5: bite sized – cookies
Week 6: Chinese New Year – mushroom bao
Week 7: new tool – baguette baker
Week 8: chocolate – chocolate peanut butter bonbons
Week 9: timed bake – under 1 hour! chocolate chip scones
Week 10: allergy/diet restriction – macarons
Week 11: quick breads – kale and cheese quick bread
Week 12: signature bake – purple cow bread
Week 13: enriched breads (kale and cheese babka fail)
Week 14: childhood favorite –fudgy triple layer chocolate cake with chocolate ganache frosting
Week 15: decorating challenge – purple velvet cake
Week 16: crispy crunchy – bacon cheddar popcorn
Week 17: p52 of a favorite cookbook, or your favorite blog – chocolate peanut butter drip cake
Week 18: pâte à choux – bacon cheese puffs
Week 19: veggies turned sweet – red velvet beet waffles
Week 20: plating – chocolate chip cookie (butter challenge)
Week 21: Birthday Party! – chocolate orange cake
Weed 22: Scandinavian – Swedish apple cake (plus a bonus sourdough discard apple cake)
Week 23: Layers – Pecan apple oat bars (post is pending)
Week 24: Tarts – rainbow fruit tart
Week 25: Bagels and donuts – maple donut cake
Week 26: Surprise inside – surprise heart yeast bread (pending)
Week 27: Local favorite – Rainier cherry crisp
Week 28: Seasonal ingredients – blackberry lemon bread
Week 29: Classic French dessert – peanut butter banana clafoutis (a classic with non-classic flavors!)
Week 30: Savory baking – pizza
Week 31: Unusual ingredient – juniper lime drizzle cake

Next week: Brunch

the kitchen sink showing all of the items used to make this peanut butter rice krispies recipe

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