The giant, delightfully indulgent cookies at Costco are legendary. That’s why, when I heard there was a new cookie-meets-Rice Krispies treat hybrid in the baked goods section, I ran to my local store to check it out. They come in a package of 24 large cookies for $9.99. Luckily I found some, because it’s been hard to find the marshmallow crispy cookies on store shelves since they went viral online. Let me tell you that from the first bite, they were so incredible, I was instantly inspired to create my own copycat Costco marshmallow crispy cookies at home.

How do the Costco Marshmallow Crispy Cookies taste?

The base of Costco marshmallow crispy cookies is a sugar cookie made with brown butter, which is is filled with crisp rice cereal for texture. There are melted marshmallows on top of the cookies that transform them into a dreamy, gooey dessert. The cereal and marshmallows in these cookies provide the nostalgic flavor and texture of a Rice Krispies bar, but for me, it was the genius twist of using brown butter that took the cookies to a whole new level. The delightfully nutty flavor from the brown butter elevated these cookies into a sophisticated treat.

How to Make Copycat Costco Marshmallow Crispy Cookies

It took me a few tries to get this copycat recipe just right. The key to success was browning only a portion of the butter used in the dough as well as chilling it before baking. This prevents the cookies from spreading too much.

Ingredients

  • 1 cup unsalted butter, softened and divided
  • 1 cup firmly packed brown sugar
  • 1/2 cup granulated sugar
  • 1 egg
  • 1 egg yolk
  • 1-1/2 teaspoons vanilla extract
  • 2-3/4 cups all-purpose flour
  • 1 teaspoon salt
  • 1 teaspoon baking powder
  • 1/2 teaspoon baking soda
  • 2 cups crisp rice cereal
  • 1 cup mini marshmallows

Directions

Step 1: Brown the butter

Place 1/2 cup (one stick) of the butter in a medium saucepan over medium heat. Gently stir until the butter begins to brown and has a nutty aroma. Remove the pan from the heat and cool the butter completely.

Step 2: Make the dough

A metal mixing bowl containing a rough, light brown cookie dough mixture sits on a textured gray surface.
Kristina Vanni for Taste of Home

In a large mixing bowl, cream together the remaining stick of butter, the cooled browned butter, brown sugar and granulated sugar until they’re light and fluffy. Add the egg, egg yolk and vanilla extract until they’re well combined.

In a separate bowl, combine the flour, salt, baking powder and baking soda. Gradually add the flour mixture to the butter mixture until they’re combined. Fold in the cereal until it’s well distributed.

Step 3: Shape and refrigerate the dough

Six unbaked cookies with white marshmallow pieces on top are evenly spaced on a parchment-lined baking sheet, ready to be baked. The background is a textured gray surface.
Kristina Vanni for Taste of Home

Using a 1/4 cup measuring cup, scoop the cookie dough and shape it into balls. Flatten each cookie dough ball slightly and press about three mini marshmallows into the top of each. Place the cookies on a tray and refrigerate them for at least one hour or up to overnight.

Step 4: Bake the cookies

When you’re ready to bake, preheat the oven to 350°F and cover your baking sheets with parchment.

Place the chilled dough on the baking sheets at least 2 inches apart. Bake the cookies for 14 minutes or until their edges begin to brown. Remove the cookies from the oven and allow them to cool completely on the baking sheet before transferring them to a wire rack.

Eight golden brown cookies with white marshmallow pieces are arranged in two rows on a black wire cooling rack, set on a gray textured surface.
Kristina Vanni for Taste of Home

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