Brown Butter Cornflake Marshmallow Skillet Cookie

Brown Butter Cornflake Marshmallow Skillet Cookie | Once Upon a Recipe

Friendssssss! Happy October!

I’ve got a skillet cookie for yer face today! You’ve seen those cornflake marshmallow cookies from Momofuku Milk Bar around the interwebs, yes? The chewy, amazing, foodgasm-inducing, cornflake/chocolate/peanut butter chip/marshmallow-studded cookies as big as your hand. Yep, those are the ones.

Brown Butter Cornflake Marshmallow Skillet Cookie | Once Upon a Recipe

Well those cookies really are all they’re cracked up to be. In fact, they’re kind of like crack. Ridiculously addicting and really not good for you at all. Why is it that things that taste so good have to be so bad? You know me though – all about the balance. Eat some kale salad, go for a run, eat a skillet cookie. Yep, balance.

Brown Butter Cornflake Marshmallow Skillet Cookie | Once Upon a Recipe

Brown Butter Cornflake Marshmallow Skillet Cookie | Once Upon a Recipe

Basically I took that cookie and turned it into a no-bowl required skillet cookie. Skillet cookies are my jam. I mean seriously, a big, warm, gooey cookie that is best served with good friends and many spoons – it doesn’t get much better. And I browned my butter, ’cause brown butter is still the cat’s meow. Annnnddd, it’s ready in about 30 minutes. So grab a few of your faves, throw this bad boy in the oven, and dig in! Treat yo’ self!

Brown Butter Cornflake Marshmallow Skillet Cookie | Once Upon a Recipe

Brown Butter Cornflake Marshmallow Skillet Cookie (adapted from Shutterbean, which was adapted from Momofuku Milk Bar)

A gooey skillet cookie full of cornflakes, dark chocolate, peanut butter chips, and marshmallows. No bowl required! Serves as few or as many as you want! 

1/2 cup (1 stick) unsalted butter
1/2 cup granulated sugar
1/3 cup brown sugar, packed
1 large egg
1/2 tsp. vanilla
3/4 cup all-purpose flour
1/4 tsp. sea salt
1/2 teaspoon baking powder
1/4 teaspoon baking soda
1 1/2 cups cornflakes
2 TBSP. dark chocolate, chopped
2 TBSP. peanut butter chips
3/4 cup mini marshmallows

Preheat oven to 350°F. Place the butter in a 10-inch cast iron skillet over medium heat. Melt and brown the butter, stirring until golden brown and fragrant (about 5-7 minutes). Remove from heat. Add the sugars and mix well. Add the egg and vanilla and stir. Add the flour, salt, baking powder, and baking soda and mix well. Fold in the cornflakes, chocolate, and peanut butter chips. Spread the batter out evenly in the skillet. Sprinkle with marshmallows. Bake for  20-25 minutes, or until golden brown. Don’t over bake, as the goal is a gooey cookie! Allow to cool slightly and then eat straight out of the skillet. Bliss!

Brown Butter Cornflake Marshmallow Skillet Cookie | Once Upon a Recipe


  1. Mmmm … I would love a cornflake cookie just by itself even without the pb and marshmallow … but of course with sounds ridiculously delicious! I do love the idea of a skillet cookie – it’s like a cross between a cookie and a gooey pudding!

  2. I have a place in my heart for cereal desserts. They’re so nostalgic for me. And the fact that this is one GIANT cookie gets me excited!

  3. I’ve never had luck making these actual cookies…but as a skillet cookie, I think I would fare much better!

    • Hi Joanne – I made them once as cookies and they turned out but were a total pain in the arse to put together. This is way easier and the results are just as delicious!

  4. Holy moly – this looks good! I can practically sense that stick-to-your-teeth goodness here! Cornflakes were my fave growing up and I’ve definitely seen those compost cookies/crack pie/cereal milk creations but have yet to have one! This may be a much easier shortcut to it all. Love the easy one huge skillet affair!

  5. when do u add the cornflakes?

    • Hi Jilli – oops, oversight on my part! You add the cornflakes along with the chocolate and PB chips. I’ve updated the recipe. Thanks for picking up on that!

  6. amazing!!!! I want a giant spoonful of this with a big lump of vanilla ice cream on top. Also, the other day, I totally thought that I am never baking with regular butter ever again. Brown butter all the way!

  7. Oh man this looks so good. I feel like I would probably end up eating the whole thing!

    • Eating a dessert in its entirety is definitely a risk you take. You can either live dangerously or make sure you’re surrounded with a few friends with cookie appetites. 😉 Thanks friend!

  8. This looks so good! It’s perfection in a pan and I just want to eat it all! I’ve only ever had cornflakes in honeyjoys as a dessert and I am addicted to those so this has just jumped to the top of the list!

  9. marianapdesousa says:

    Is it wrong I want this for breakfast tomorrow?

  10. whiskandshout says:

    I loooove skillet cookies! Cornflakes in dessert are my favorite 🙂

  11. I think you must be trying to kill me. Oh my, this looks insanely good.

  12. This is one of the most glorious skillet cookies we have seen! Just need 2 spoons…

  13. Wow this just looks incredible!! I need to get me a cast iron skillet!

  14. oooohh man this looks amazing!!! Like the kind of amazing that I’d need to eat salad for a week straight to enjoy. I guess I already eat a lot of salad, so I probably deserve one of these

  15. This looks sooooo good! I wish I could cook and bake like you! (So does my husband.) ; )

  16. Oh my gosh Amanda! This looks sinfully good. The kind of good you eat straight out of the skillet while it’s hot!

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