5-Ingredient Peanut Butter Cornflake Bars (No Bake)

No Comments

This post may contain affiliate links. Please read my disclosure for more info.

If you’re looking for a crowd pleasing treat that’s also ridiculously easy to make, these no-bake peanut butter cornflake bars won’t disappoint. They’re the perfect mix of crunchy, chewy and chocolaty. The best part? You only need 5 very simple ingredients – cornflakes and peanut butter of course, plus marshmallows and butter and chocolate for the top. And they’re no bake, so no need to turn on the oven.

Closeup of someone holding a peanut butter cornflake bar with a bite out of it and with more bars below and around it.

Why you’ll love them

Quick and fuss-free. With just 5 simple ingredients, you can make peanut butter cornflake bars in just a few minutes – and all in one pan on the stove top.

No-bake. No need to turn on the oven, which is always a bonus, but especially in Summer!

A family-friendly recipe. Definitely not just for kids, although they’ll love helping you to make them – and then eat them! Grown-ups will love the winning combinations of sweet-and-salty, crispy-and-chewy in these bars that will have everyone coming back for seconds – and thirds!

Perfect on-the-go snack. You could call these cereal bars with peanut butter, which makes them a not-too-bad-for-you easy treat, right? Great for school snacks, picnics, parties or hiking treats!

Budget-friendly. Just a handful of affordable ingredients.

Giftable and shareable. Pack them up into a pretty box and share with friends, family members, neighbours or co-workers. Trust me, these will bring to a smile to anyone’s face!

About the ingredients

A collage of all the ingredients needed to make a 5-ingredient peanut butter cornflake bar recipe including cornflakes, peanut butter, marshmallows, butter, chocolate and marshmallows.

Butter: To add a hint of buttery taste to your corn flake bars. I actually like to use salted butter since they have a caramel-y taste, but unsalted works too.

Peanut butter: I prefer to use a natural crunchy peanut butter, but really any peanut butter is fine. The bars don’t have a strong peanut butter flavor – it just combines with the other ingredients to make a slightly nutty and very tasty ‘caramel’.

Feel free to use another kind of nut butter such as almond butter. Or use a seed butter such as sunflower butter if you want to avoid nuts altogether.

Marshmallows: Small or medium sized marshmallows are best since they’ll melt more easily into the other ingredients. I usually grab a bag of mixed pink and white marshmallows. This does give the ‘caramel’ a slight pink hue, but it isn’t unpleasant at all. If you prefer to use all white marshmallows, however, that’s absolutely fine!

Leftover marshmallows? You’re in luck! I wrote this list of 74 easy marshmallow recipes.

Cornflakes: There are no rules here. Simply grab an affordable box of cornflake cereal, or whatever you already have in the pantry.

Chocolate: I typically use dark chocolate which I think keeps the corn flakes bars from tasting overly sweet. However, milk chocolate is fine too if you prefer. I like to choose a good quality chocolate. Use a bar broken into pieces or chocolate chips.

How to make peanut butter cornflake bars

Firstly, line a square or rectangular baking pan with baking paper.

In a large saucepan, combine the butter, peanut butter, and marshmallows. Heat ON A LOW HEAT, stirring from time to time, until smooth and well combined. This will only take a few minutes.

At this point, your kitchen will start to smell divine!

Collage of 2 images showing marshmallows, peanut butter and butter in a pan overhead and then melted together and with a wooden spoon in it.

Then, pour in the cornflakes and fold and stir well until all the cornflakes are well covered in the delicious sticky mixture.

Collage of two images showing peanut butter marshmallow mixture in a pan overhead with a spoon in and again with cornflakes added in.

Pour the cornflake mixture into the lined pan and press down and into the corners until you have a flat and fairly even layer.

Collage of 2 images showing someone pressing peanut butter cornflake mixture into a large rectangular baking dish.

Break the chocolate up into a microwave safe bowl. Melt for around 1.5 minutes in 30-second bursts (Alternatively you can melt in a bowl suspended over a pan of boiling water, making sure the bowl doesn’t touch the water).

Then spread the melted chocolate evenly over the top of the cornflake peanut butter bars.

A collage of two images showing overhead of a baking dish with someone spreading melted chocolate onto cornflake bars and then with the chocolate all spread over the top.

Cut into squares. Then cover with plastic wrap and let set in the fridge before letting everyone grab and enjoy!

Overhead of peanut butter cornflake bars cut into squares on baking paper with a few cornflakes scattered around.

Helen’s top tips

Work quickly once you’ve added the cornflakes to the peanut butter and marshmallow mixture – before it starts to cool and get stickier to work with.

Spread the chocolate evenly right to the edges of the cornflake crunch. It might seem like there isn’t a lot of chocolate, but don’t worry. It’ll run into the cracks and crevices of the cornflake mixture and once set you’ll see it’s the perfect layer of chocolate!

I usually cut into squares BEFORE letting the chocolate set in the fridge. This way, the chocolate topping doesn’t crack when you cut into it.

Closeup of 3 peanut butter cornflake bars on top of each other with a bite out of the top one, all on baking paper with more bars at the side and a few cornflakes and with the empty melted chocolate jug in the background.


This is the sort of easy chocolate dessert that’s perfect just as it is. However, in case you’d like to switch things up a little, here are a few ideas.

  • Add peanuts or another type of nut, either crushed or whole, to the cornflake mixture. About half a cup should be perfect.
  • As previously mentioned, it’s perfectly acceptable to use a different kind of nut butter instead of peanut butter. Or, if you’d like to avoid nuts for any reason, try the recipe with sunflower butter or another peanut free alternative.
  • Add a little coconut to the mixture. Try a quarter of a cup, and also sprinkle a little on top of the chocolate before it sets.
  • Try adding a little dried fruit such as dried cranberries, raisins or chopped dried apricots. For these versions, I think white chocolate on the top would go well.
  • No cornflakes in the pantry but got another similar cereal such as Rice Krispies, Special K or Cheerios? Of course, this recipe will still work perfectly well with all of those and more. Give it a try!
  • For an even more peanut buttery vibe, add chopped Reese’s peanut butter cups both into the corn flake mixture and sprinkled over the top of the chocolate. Or try your favorite candy bar or candy, such as chopped Snickers, Maltesers or M&Ms.

In fact, I have another version of these no bake peanut butter bars made with Cheerios instead (which are usually gluten-free, but do check the packaging to be sure). Interested? Check out the peanut butter cheerio bars as well.

Recipe FAQs

Are cornflakes gluten-free?

No, generally they are not. Cornflakes themselves are typically made from corn, which is naturally gluten-free. However, they can often also contain corn or malt syrup which contain gluten. However, it is possible to buy cornflakes which are labelled gluten free. Read the ingredients carefully to check.

How long do cornflake bars last in the fridge?

Once they are firm and set, you can store them in an airtight container in the refrigerator for up to a week. The cornflakes may soften slightly as the days go on, but they’ll still taste great. Alternatively, you can freeze them in freezer bags or a freezer safe container for up to 3 months.

More no-bake treats

  • These peanut butter cheerio bars are the original recipe that inspired these peanut butter cornflake treats. I hope you try those too to see which you prefer!
  • Hedgehog slice! A classic and easy Australian chocolate biscuit cake recipe you’ll absolutely love.

Love super quick and easy desserts that you don’t have to turn on the oven for? Check out this list of best 5-minute no bake desserts.


Want to save this recipe?
Just enter your email and get it sent to your inbox! Plus you’ll get new recipes from us every week!
Please enable JavaScript in your browser to complete this form.
Closeup of 3 peanut butter cornflake bars on top of each other with a bite out of the top one, all on baking paper with more bars at the side and a few cornflakes and with the empty melted chocolate jug in the background.
No ratings yet

5-Ingredient Peanut Butter Cornflake Bars

Looking for a crowd-pleasing party treat or emergency sweet stash? These 5-ingredient peanut butter cornflake bars have you covered! Quick, crunchy, chewy, and chocolaty – they're not just for kids!
Prep: 5 minutes
Cook: 10 minutes
Total: 15 minutes
Servings: 20 -30


  • 2 ounces butter, (about 3 tablespoons)
  • ½ cup peanut butter
  • 10 ounces marshmallows
  • 6 cups cornflakes, = 6 ounces (use 5 cups if using UK/Australian cups)
  • 7 ounces chocolate, milk or dark


  • Line a 9 x 13 inch pan (or similar) with baking paper.
  • Melt the butter, peanut butter and marshmallows together slowly on a low heat.
    2 ounces butter, ½ cup peanut butter, 10 ounces marshmallows
  • Combine with a wooden spoon, then stir in the cornflakes.
    6 cups cornflakes
  • Press the mixture into the pan with slightly damp hands to prevent sticking.
  • Melt the chocolate in the microwave for 90 seconds (in 30-second bursts), then pour over the cornflake mixture, spreading right to the edges.
    7 ounces chocolate
  • Cut the cornflake bars into 20 – 30 bars while the chocolate is still wet. Cover the whole pan with plastic wrap, then let set in the refrigerator for at least an hour until the chocolate is set.
  • Store covered tightly or in an airtight container for up to a week. Alternatively, freeze in Ziploc bags or a freezer proof container or freezer bags for up to 3 months.


Measuring the cornflakes: If you’re using UK/Australian cups (slightly larger than US cups), use just 5 cups of cornflakes (about 150 grams). Don’t worry about being super precise – it won’t ruin the recipe!
Remember to melt your butter, peanut butter and marshmallows ON A LOW HEAT. You don’t want it to boil up into a super chewy caramel!
Storage: Surprisingly, these peanut butter cornflake treats stay crispy for up to a week in an airtight container or well covered in the fridge. If you want to keep them longer, store in the freezer in Ziploc bags for up to 3 months.
Variations: Add peanuts, coconut, dried fruit or chopped candy to the cornflake mixture if you like. You can also sprinkle coconut, chopped Reese’s pieces or other small candy over the top of the melted chocolate if you like.
Peanut butter: Feel free to use a different kind of nut butter such as almond if you prefer or in case of allergies. You can even use sunflower butter or a different alternative to peanut butter.


Calories: 184kcal, Carbohydrates: 26g, Protein: 3g, Fat: 9g, Saturated Fat: 4g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 3g, Trans Fat: 0.1g, Cholesterol: 6mg, Sodium: 120mg, Potassium: 81mg, Fiber: 1g, Sugar: 15g, Vitamin A: 221IU, Vitamin C: 2mg, Calcium: 7mg, Iron: 3mg
Like this recipe? Rate and comment below!

About Helen Schofield

Don't expect to find anything fussy or complicated here. Just QUICK, EASY & (mostly!) HEALTHY recipes from the Mediterranean and beyond. ENJOY!

You May Also Like:

Leave a comment

Your email address will not be published. Required fields are marked *

Recipe Rating

This site uses Akismet to reduce spam. Learn how your comment data is processed.