It’s cookie season! I decided to try a recipe I had earmarked for a while now: Momofuku Cornflake Marshmallow Chocolate Chip Cookies. I read a lot of great things about this cookie, and I decided it was finally time to make some for myself.
The first step to making these cookies is preparing the Cornflake Crunch. This involves cornflake cereal, milk powder, sugar, salt, and butter being baked at a low heat, and then cooled to room temperature.

The Cornflake Crunch must be cooled to room temperature before adding it to the cookie dough.

As the Cornflake Crunch cooled, I prepared the cookie dough. The ingredients required for this recipe are not different from a lot of chocolate chip cookies, except for the marshmallows.


The recipe makes it very clear that you should not over-mix the cookie dough. It’s very tempting to keep on mixing to ensure all the ingredients are distributed evenly, though.


I scooped out all of the dough onto a cookie sheet and popped it into the fridge for a few hours. However, I found that it was important to scoop and then flatten each scoop of dough before refrigerating.


My first batch was a flop; my cookies looked like flat caramel discs. Luckily I only baked 4 cookies at a time. I followed the instructions and decided that the temperature was too high, and the bake time was too long, at least for my oven. I reduced the heat to 350 degrees F, turned on the convection fan, and baked the rest of my cookies for 10-12 minutes instead of 18 minutes. They turned out much better than the first batch did.

The reduced temperature resulted in melting the marshmallows, rather than caramelizing them. This made for a nice gooey, chewy cookie with a nice crunch with help from the Cornflakes!

If you don’t plan on freezing them, these cookies are best eaten the day they’re baked (especially when they’re still warm), in my opinion. They’re good the next day, but I definitely noticed a loss of freshness by the third day.

Cornflake Marshmallow Chocolate Chip Cookie Recipe
Ingredients
- 16 tablespoons (2 sticks)/225 g butter, at room temperature
- 1 1/4 cups/ 250 g granulated sugar
- 2/3 cup/ 150 g tightly packed light brown sugar
- 1 egg
- 1/2 teaspoon/ 2 g vanilla extract
- 1 1/2 cups/ 240 g flour
- 1/2 teaspoon/ 2 g baking powder
- 1/2 teaspoon/ 1.5 g baking soda
- 1 1/2 teaspoons/ 5 g kosher salt
- (3 cups) Cornflake Crunch
- 128g Cornflakes
- 30g milk powder
- 30g granulated sugar
- 3g kosher salt
- 98g unsalted butter, melted
- 2/3 cup/ 125 g mini chocolate chips
- 1 1/4 cups/ 65 g mini marshmallows
Cornflake Crunch Instructions:
1. Heat the oven to 275°F.
2. Pour the cornflakes in a medium bowl and crush them with your hands to one-quarter of their original size. Add the milk powder, sugar, and salt and toss to mix. Add the butter and toss to coat. As you toss, the butter will act as glue, binding the dry ingredients to the cereal and creating small clusters.
3. Spread the clusters on a parchment- or Silpat-lined sheet pan and bake for 20 minutes, at which point they should look toasted, smell buttery, and crunch gently when cooled slightly and chewed.
4. Cool the cornflake crunch completely before using.
Cookie Instructions:
1. Combine the butter and sugars in the bowl of a stand mixer fitted with the paddle attachment and cream together on medium-high for 2 to 3 minutes. Scrape down the sides of the bowl, add the egg and vanilla, and beat for 7 to 8 minutes.
2. Reduce the mixer speed to low and add the flour, baking powder, baking soda, and salt. Mix just until the dough comes together, no longer than 1 minute. (Do not walk away from the machine during this step, or you will risk overmixing the dough.) Scrape down the sides of the bowl with a spatula.
3. Still on low speed, paddle in the cornflake crunch and mini chocolate chips just until they’re incorporated, no more than 30 to 45 seconds. Paddle in the mini marshmallows just until incorporated.
4. Using a 2-ounce ice cream scoop (or a 1/3-cup measure), portion out the dough onto a parchment-lined sheet pan. Pat the tops of the cookie dough domes flat. Wrap the sheet pan tightly in plastic wrap and refrigerate for at least 1 hour, or up to 1 week. Do not bake your cookies from room temperature—they will not hold their shape.
5. Heat the oven to 350°F, convection.
6. Arrange the chilled dough a minimum of 4 inches apart on parchment- or Silpat-lined sheet pans. Bake for 10-12 minutes. The cookies will puff, crackle, and spread. At the 10-minute mark, the cookies should be browned on the edges and just beginning to brown toward the center. Leave them in the oven for an additional minute or so if they aren’t and they still seem pale and doughy on the surface.
7. Cool the cookies completely on the sheet pans before transferring to a plate or to an airtight container for storage. At room temperature, the cookies will keep fresh for 5 days; in the freezer, they will keep for 1 month.
Modified recipe from Momofuku Milk Bar by Christina Tosi (Clarkson Potter, 2011).