Peanut Butter Marshmallow Cornflake Slice! Get ready for a taste sensation that's out of this world. These chewy cornflake treats are packed with creamy peanut butter, fluffy marshmallows, and topped with a blanket of rich dark chocolate!
Each bite is like a burst of magic in your mouth, with the nutty goodness of peanut butter dancing with the sweetness of marshmallows. They're super chewy and totally lush, and don't forget the finishing touch: a sprinkle of flaky sea salt for that extra zing! Get ready to treat your taste buds to something extraordinary.

The ultimate snack for lunch boxes, party platters, or simply satisfying your snack cravings. These cornflake slice are a breeze to whip up, and they're so delicious, even the kids can get in on the fun! They're the go-to treat for any occasion, whether you're hosting a party or just need a quick pick-me-up.
Plus, they're a guaranteed hit at potluck gatherings. With their irresistible flavor and easy preparation, they're sure to become your new favorite dessert go-to! Check out my pistachio white chocolate blondies and s mores blondies!
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Why you'll love this recipe
- Divine Peanut Butter Cornflake Flavor: Rich, nutty taste of peanut butter perfectly complemented by the crunchy texture of cornflakes. This corn flake slice recipe combines these two beloved flavors to create a divine taste sensation that's utterly irresistible. Each bite is a harmonious blend of sweet and savory, making it a treat for the taste buds that's hard to resist.
- Chewiness from the Marshmallows: The marshmallows in this recipe add a delightful chewiness like my chocolate covered rice krispies that takes these to the next level. As you sink your teeth into each slice, you'll experience a satisfyingly soft and gooey texture that's pure bliss.
- Ease of Making Them: One of the best things about this recipe is just how easy it is to make. With simple ingredients and straightforward instructions, anyone can whip up a batch of these delicious slices in no time. edible Biscoff cookie dough is also no bake!!
Equipment
Large Pot will make your life much easier! The cornflakes will go everywhere if your pot isn't big enough when making this cornflake slice recipe easy!
Ingredients
- Smooth and Creamy Peanut Butter (Not Natural): Smooth and creamy peanut butter is ideal for this recipe because it provides a velvety texture and consistent flavor throughout the treats. Unlike natural peanut butter, which tends to separate and can have a gritty texture, smooth and creamy peanut butter blends seamlessly with the other ingredients, ensuring a smooth and indulgent mouthfeel in every bite.
- Regular and Unsweetened Cornflakes: Regular, unsweetened cornflakes are preferred for this recipe to maintain the balance of flavors and textures. Sweetened cornflakes may result in overly sweet flavor, overpowering the natural sweetness of the marshmallows and dark chocolate topping. I like Kellog's. Don't use honey cornflakes.
- Original Marshmallows (Not Vegan): Original marshmallows, which contain gelatin derived from animal sources, are traditionally used in this recipe for their classic flavor and texture. These marshmallows melt smoothly and evenly, creating a luscious, chewy texture. Chocolate ice cream with marshmallow is amazing!!
See recipe card for quantities.
Substitutions
- Brown the butter for extra nutty goodness! Brown butter makes everything better. It would be amazing in these corn flake squares. Brown butter blondies are so good.
- Honey in these would be amazing, honey cornflake flavor is very nostalgic and would go so well with cornflake marshmallow.
- Skip the chocolate on top if you're not a fan, but don't skip finishing them with flaky sea salt.
- If you want more crunch and texture, chopped up peanuts on top of the chocolate would be incredible!
This recipe has not been tested with other substitutions. These are just suggestions.
Instructions
Let's make cornflake chocolate slices!
Step 1: Line an 8X8 pan with parchment paper.
Step 2: In a large pot over medium heat, melt the butter and marshmallows. Stirring until completely melted.
Step 3: Take the pot off of the heat. Add the peanut butter, mix until combined and melted.
Step 4: Pour in the cornflakes, Mix until almost combined, pour in the mini marshmallows. Mix until completely combined and coated.
Step 5: Pour into the parchment lined pan. Spread it out evenly, making sure to push it down a bit to get into the corners of the pan.
Step 6: Pour the melted chocolate over the top, spreading it out evenly. Place in the refrigerator until the chocolate is set. Take out and top with flaky sea salt. Cut into bars and enjoy!
Hint: Top with flaky sea salt before eating, it makes the flavors pop and cuts the sweetness!
Pro tips
- When mixing the marshmallows into the cornflake and peanut butter mixture, reserve 1 cup of marshmallows and gently fold them in at the end. This ensures you have pockets of gooey marshmallow goodness throughout the slices, adding amazing texture and chewiness.
- Line the baking pan with parchment paper before pressing the mixture into it. This not only prevents the slices from sticking to the pan but also makes cleanup a breeze. Once the mixture is in the pan, use the parchment paper to press it down evenly and compactly. .
- Opt for dark chocolate when preparing the topping to balance out the sweetness of the marshmallows and peanut butter. The slight bitterness of dark chocolate complements the sweetness of the other ingredients, creating a more complex and satisfying flavor profile. Plus, dark chocolate adds a rich and decadent layer that takes these to the next level!
FAQ
How can I store this cornflake slice?
Place the slices in an airtight container or sealable plastic bag to prevent them from drying out. Store the container at room temperature, away from direct sunlight or heat sources. Enjoy within 5 days for optimal freshness and flavor.
Can I double the recipe?
Yes! You can use a 9X13 pan and just double all of the ingredients.
Is this recipe gluten free?
You can try to find gluten free Cornflakes! Always check all of the other ingredients for gluten as well.
Storage
Room Temperature
Place the slices in an airtight container or sealable plastic bag to prevent them from drying out. Store the container at room temperature, away from direct sunlight or heat sources. Enjoy within 5 days for optimal freshness and flavor.
Refrigeration
It's best not to refrigerate the slices, as this can alter their texture and make them overly firm or dry. Keep them at room temperature for the best taste and texture.
Freezer
If you'd like to extend the shelf life, you can freeze the slices. Place them in an airtight container, separating layers with parchment paper to prevent sticking. When ready to enjoy, thaw the slices in the refrigerator overnight or at room temperature for a few hours.
Related
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📖 Recipe
Cornflake Slice
Equipment
- 8X8 baking pan
- Large metal pot
- Mixing bowls
- Measuring Cups
- Rubber Spatula
Ingredients
- 5 tablespoons (71 grams) salted butter
- 5 cups (283 grams) marshmallows for melting
- ½ cup plus 2 tablespoons (157 grams) peanut butter creamy, not natural (I like Skippy)
- 4.5 cups (161 grams) Cornflakes cereal unsweetened (I like Kellog's)
- 1 cup (62 grams) mini marshmallows do not melt
Topping
- 1 cup (166 grams) dark chocolate melted
Instructions
- Line an 8X8 pan with parchment paper. In a large pot over medium heat, melt the butter and marshmallows. Stirring until completely melted.
- Take the pot off of the heat. Add the peanut butter, mix until combined and melted.
- Pour in the cornflakes, Mix until almost combined, pour in the mini marshmallows. Mix until completely combined and coated.
- Pour into the parchment lined pan. Spread it out evenly, making sure to push it down a bit to get into the corners of the pan.
- Pour the melted chocolate over the top, spreading it out evenly. Place in the refrigerator until the chocolate is set. Take out and top with flaky sea salt.
- Cut into bars and enjoy!
Kelsey says
Oh my gosh these were such a hit!
Amanda says
so happy to hear it!! 🙂