How to Make Costco Marshmallow Crispy Cookies at Home

These Costco Marshmallow Crispy Cookies have been blowing up on social media since Costco released them in August of this year. They are the perfect chewy brown butter cookie, with crunchy rice krispies cereal, and pools of ooey gooey marshmallow from the mini marshmallows mixed in there.

People everywhere are going crazy over these new Costco Marshmallow Crispy Cookies and let me tell you why! This new bakery item is soft, chewy, packed with pockets of melty marshmallow, and balanced perfectly with a light crunch from the crispy rice cereal. This cookie is honestly the best with this iced brown sugar coffee!

By browning the butter and adding a touch of corn syrup, you get a cookie that’s full of flavor, extra chewy, and slightly caramel-y. If you’ve ever grabbed a cookie from Costco and thought, “I wish I could make this at home,” now you can! Or if you don’t have a Costco membership but have been wanting to give these new cookies a try, here’s your chance.

Do these taste exactly like the Costco cookies?

In my humble opinion, I think they taste better than the costco cookies but something we have to keep in mind is that industrial baked goods always have a slightly different mouthfeel as well as a different taste because they aren’t made with regular ingredients you and I have at home.

This recipe at Costco, for example, uses mainly shortening with a butter flavoring to get them to look, taste, and feel the way they do. In this copycat recipe, we used mainly butter that we browned to get that nutty flavor with a little shortening to keep it moist and chewy, since not everyone has brown butter flavoring on hand.

So keep all of this information in mind when making these! You can look at the image above to see all of the ingredients that are used in the cookie itself from Costco to compare to what we are using in this recipe. If you are feeling adventurous you can play around with ratios or add new things that I maybe didn’t add from the ingredients above. Just know you might get a completely different result. , you can play around with ratios or add new things that I may not have adde

Ingredients for these homemade costco marshmallow crispy cookies

Here are the ingredients you will need to make these new marshmallow crispy cookies from Costco. Scroll down to the recipe card at the bottom of the page for the detailed ingredient measurements. 

• Unsalted Butter: browns slightly to deepen the cookie’s flavor.
• Shortening: adds extra chewiness and helps cookies hold their shape without spreading too much.
• Dark Brown Sugar: gives moisture and a subtle caramel flavor.
• Granulated Sugar: adds sweetness and slight crispness.
• Egg + Egg Yolk: helps bind all the ingredients together.
• Vanilla Extract: enhances the flavor.
• All-purpose Flour: provides structure for the cookie dough.
• Cornstarch: is optional but adds extra softness.
• Baking Powder and Soda: leavens and aerates the cookies.
• Kosher Salt: balances sweetness and enhances all the flavors.
• Light Corn Syrup: adds chewiness.
• Mini Marshmallows: gives soft pockets of sweetness and chewy texture throughout.
• Rice Krispies Cereal: added to the dough makes this delicious treat taste like a rice krispies treat cookie.

How to make copycat Costco marshmallow crispy cookies at home

This is how you can make a copycat version of the Kirkland Signature marshmallow crispy cookies. Make sure to scroll down to the recipe card at the end of this post for the full step-by-step instructions! 

1. Melt your butter in a light-colored saucepan over medium heat. Stir constantly. Keep an eye out as it foams and then starts to develop golden brown bits at the bottom. Pour it into a heatproof bowl, scraping in all those flavorful browned bits, and let it cool until slightly thickened.
2. In a mixing bowl, beat together the browned butter, shortening, dark brown sugar, and granulated sugar until the mixture is light and fluffy.
3. Mix in the corn syrup, egg, egg yolk, and vanilla until everything is smooth and perfectly combined.

4. In a separate bowl, whisk together the flour, cornstarch, baking soda, baking powder, and salt. Gradually add the dry ingredients to your wet ingredients and mix until just combined and without over-working the dough.
5. Gently fold in the Rice Krispies and some of the mini marshmallows. The marshmallows should be chilled so they don’t melt into goo too early.
6. Cover the brown butter dough and pop it in the fridge for 1 hour. This step helps the cookies hold their shape, keeps the marshmallows from oozing too much, and prevents excessive spreading.

7. Preheat your oven and line a cookie sheet with parchment. Scoop out roughly 3-tablespoon portions and give them plenty of space. Bake in the preheated oven until the edges are golden, but the centers are still slightly underbaked.

8. As soon as the cookies come out of the oven, use a larger cookie cutter than the size of the cookies to swirl them around (see the photos below) so that they are a perfect circle and keep any marshmallow that could’ve oozed out inside.
9. Working quickly, take a few mini marshmallows, break them in half, and stick them on the hot cookies to give them that signature Costco cookie look.
10. Let the cookies sit on the baking sheet before moving them to a wire rack. The marshmallows will firm up as they cool, giving you that perfect chewy-and-crispy combo.

Tips and Tricks for the best cookie

• If you love a super soft, chewy cookie, swap the granulated sugar for all brown sugar. It adds moisture and a deeper caramel flavor.
• Don’t overbake. The edges should be golden, but the centers should still look slightly soft when you pull them from the oven.
• Chilling the dough overnight produces thicker cookies and lets the flavors develop more.
• Use a kitchen scale instead of measuring cups to weigh the ingredients with better accuracy.
• Use a light-colored saucepan for browning butter to help you see when it reaches that perfect golden stage without burning.

Why do you need to make these krispy marshmallow cookies?

• This recipe is perfect for people who aren’t Costco customers or just don’t have a local store in their area.
• If you’re already a fan of the cookies but don’t want a huge 24-count container or want to reduce the cookie size, this recipe is for you.
• The texture is absolute perfection with the soft and gooey marshmallow and the crispy cereal combined in an ultra-chewy cookie.
• They’re unique cookies and a great choice for parties, baked goods sale, or just an indulgent snack at home.
• They don’t use the usual preservatives that you find at industrial bakeries.

Frequently asked questions – FAQ

Can I make smaller cookies instead of the giant Costco size?

Absolutely! Just keep in mind that smaller cookies will bake a little faster, so watch them closely and pull them out when the edge of the cookie is golden but the center is still soft.

Can I make the dough ahead and freeze it?

Yes! You can do so by scooping the dough into balls, freezing them on a baking sheet, then transfer them to a freezer bag once they’re frozen solid. You can bake them straight from frozen by just adding 1–2 extra minutes to the baking time.

Can I substitute the Rice Krispies cereal?

You can, but Rice Krispies are ideal for the light, crispy texture that balances the chewy marshmallows. Other cereals may change the texture or flavor.

How should I store these copycat Costco marshmallow crispy cookies?

Store your leftover cookies in an airtight container at room temperature for 3 days or in the fridge for 5 days. My favorite secret to keep cookies extra soft if to add a pice of toast or tortilla with them in an airtight container, perfectly chewy cookies every time!

Can I make a gluten-free version of this recipe?

I haven’t personally tried it but I’m sure you can as long as you swap the all-purpose flour for a 1:1 gluten-free flour blend. You may need to slightly adjust the baking time depending on your blend.