Marshmallow Cornflake Treats


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Chewy, crunchy marshmallow cornflake treats are a twist on nostalgic Rice Krispie treats. And if you haven’t had these treats made with crunchy cornflakes, a double dose of marshmallows, and sprinkles, get ready for something fun!

removing a slice of marshmallow cornflake treat from a sheet pan

There’s something magical about biting into a thick, crunchy marshmallow cornflake bar. Is it the ooey-gooey butter and marshmallow that binds the cereal together? Or is it the nutty, sweet crunch of the corn flakes? Cereal dessert bars bring back so many fun childhood memories, but this version is unlike any other I’ve had before. 

Although they’re made just like Rice Krispie treats, the cornflakes give them a nutty crunch that really stands out. Plus lots of sprinkles just for fun.

What are Marshmallow Cornflake Treats?

Marshmallow cornflake treats are an easy cereal dessert bar made by combining melted butter and mini marshmallows with corn flakes. These yummy, sticky-sweet treats are a new take on an old favorite: Rice Krispie treats. 

Fun fact about Rice Krispie treats: they were inspired by a totally different cereal-marshmallow dessert. In her 1938 cookbook, It’s Fun to Cook, Lucy Mary Maltby had the idea to mix puffed wheat square cereal with molasses, butter, and sugar to make the first known cereal bars. 

adding marshmallow mixture to cornflakes in a metal mixing bowl

How to Make Them

  1. Make the bars. Melt the butter and marshmallows in a saucepan. Combine with the cornflakes. Add the remaining mini marshmallows and nonpareils. 
  2. Shape and set. Spread the mixture into the prepared baking pan. Top with the remaining sprinkles. 
  3. Slice and serve. When cooled, slice into squares and serve!


  • Cornflakes – Generic or name brand cornflake cereal can be used in this recipe. 
  • Unsalted Butter – Always use unsalted butter in marshmallow cornflake treats to keep this easy dessert sweet, rather than salty.
  • Mini Marshmallows – Using two standard 10 ounce-sized bags of mini marshmallows will make measuring the marshmallows easy. Just be sure to use the mini size, rather than the regular, s’more-sized marshmallows.
  • Nonpareil Sprinkles – Nonpareil sprinkles are small, round decorative sugar sprinkles that come in just about every color imaginable. You can find rainbow mixes in the baking aisle of your local grocery store, or order speciality colors online.
ingredients for a cornflake treats on a grey countertop

Make Ahead

This treat is best enjoyed the day you make them while the cereal is still crispy under all of the ooey-gooey goodness. If you need to make a batch ahead, store them in a sealed container at room temperature for up to 4 days. 

How to Store

Store these marshmallow cornflake treats in an airtight container for up to 4 days at room temperature. You can also freeze individual slices in a sealed container for 2 to 3 months. Bring to room temperature before serving.

Recipe Tips

  • Use colorful marshmallows like pink or baby blue for baby showers, bridal showers, or for perfectly pastel spring-themed cornflake bars.
  • Mix-in green and red nonpareil sprinkles for a festive holiday treat.
  • Minimize the stickiness of these marshmallow treats by spraying the stirring spoon and your cutting knife with nonstick cooking spray first. 
  • To keep your hands from getting sticky when pressing the mixture into the pan, use an extra piece of parchment paper or a butter wrapper to press down on the top as you make the surface flat.


  • Try a different cereal – Frosted Flakes, Fruity Pebbles, Cocoa Pebbles, or Chocolate Rice Krispies are all fun variations.
  • Add mix-ins – Include mini chocolate chips or chopped up candy bars for a sweet surprise.
marshmallow treats pressed into a metal baking pan


Can these be made vegan?

Yes! Turn these marshmallow cornflake treats vegan by using vegan butter and marshmallows. 

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removing a marshmallow cornflake treat from a lined pan
5 from 2 votes

Marshmallow Cornflake Treats

Melted marshmallows, butter, and toasted corn flakes are all you need to make these easy marshmallow cornflake treats! This chewy cereal bar is a family favorite.
To adjust the servings in this recipe, click on the number next to servings.
Prep: 5 minutes
Cook: 15 minutes
Total: 20 minutes
Servings: 12


  • 9×13 Baking Dish
  • Saucepan
  • Parchment Paper


  • 6 cups cornflakes
  • 3 tablespoons unsalted butter
  • 2 10 ounce bags mini marshmallows, divided
  • 1/2 cup nonpareil sprinkles, divided


  • Line a 9×13 inch baking pan with parchment paper.
  • Pour the cornflakes into a large mixing bowl.
  • In a heavy-bottomed saucepan over medium heat, melt the butter. Add one 10-ounce bag of mini marshmallows and stir until completely smooth and melted. As soon as the marshmallows are melted, pour them over the cornflakes.
  • Gently stir together the cornflakes and marshmallows until evenly combined. Next add the remaining 10-ounce bag of marshmallows and 5 tablespoons of nonpareils and fold everything together until even.
  • Spread the cornflakes out into the prepared baking pan, pressing firmly down on the top to create a flat surface. (Note: You can use an extra piece of parchment paper to press down on the top to make the surface flat.)
  • Sprinkle the remaining sprinkles over the top of the treats. Let them cool completely at room temperature.
  • When cooled, slice into squares and serve!
  • These are best if served the same day they’re made when they’re the most crisp. But you can store them in a sealed container at room temperature for up to 4 days.


These marshmallow treats are sticky! To help minimize sticking, you can spray the spoon you use to stir them and the knife you use to cut them with nonstick cooking spray first. 


Calories: 104kcal | Carbohydrates: 18g | Protein: 1g | Fat: 3g | Saturated Fat: 2g | Polyunsaturated Fat: 0.1g | Monounsaturated Fat: 1g | Trans Fat: 0.1g | Cholesterol: 8mg | Sodium: 103mg | Potassium: 24mg | Fiber: 0.5g | Sugar: 7g | Vitamin A: 338IU | Vitamin C: 3mg | Calcium: 2mg | Iron: 4mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Author: Jess Smith via Inquiring Chef
Cost: $5.00
Calories: 104
Keyword: easy dessert recipe, easy recipe, easy snack, kid-friendly recipe, make with kids, sweet treats
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About Jess Smith

Jess is the recipe creator and photographer at She spent nearly a decade as the Chief Recipe Developer for the award-winning meal planning app Cook Smarts. Her colorful, healthyish recipes have been featured in popular online publications including Parade, Hallmark, and HuffPost.

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