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These Costco Marshmallow Crispy Cookies have been blowing up on social media since Costco released them in August. 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,” you can now! Or if you don’t have a Costco membership but have been wanting to try these new cookies, here’s your chance.
Quick Look: Costco Marshmallow Crispy Cookies
- 🍪 What it is: Chewy brown butter cookies loaded with Rice Krispies and gooey mini marshmallows.
- ⭐ Why it works: Browned butter and a touch of corn syrup make them nutty, extra chewy, and slightly caramel-y.
- 💛 Why you’ll love it: Costco’s viral bakery cookie at home, no membership or 24-count tub required.
- ⚠️ What to watch for: Chill the dough a full hour so the marshmallows don’t ooze and spread.
- 🍳 Pan notes: Swirl a larger cookie cutter around each hot cookie for a perfect circle.
- ❄️ Make ahead: Freeze dough balls and bake straight from frozen with 1 to 2 extra minutes.
- 🎯 How close to the original: Browned butter replaces Costco’s shortening and butter flavoring, and I think it tastes better.
Table of Contents
- Quick Look: Costco Marshmallow Crispy Cookies
- Do these taste exactly like the Costco cookies?
- Key Ingredients
- How to make copycat Costco marshmallow crispy cookies at home
- Expert Tips
- Why This Recipe Works
- Costco Marshmallow Crispy Cookies FAQs
- More Krispy Treat Recipe Favorites
- Costco Marshmallow Crispy Cookies Copycat Recipe
Do these taste exactly like the Costco cookies?
In my humble opinion, they taste better than the Costco cookies, but keep in mind that industrially baked goods always have a slightly different mouthfeel and taste because they aren’t made with the same ingredients you and I have at home.
This Costco recipe, for example, uses mainly shortening with a butter flavoring to make them 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. If you love that browned butter flavor, you’ll also want to bake a batch of these brown butter scoopable chocolate chip cookies, which use the same nutty browned butter base.
So keep all of this information in mind when making these! You can look at the image above to see all the ingredients used in the cookie itself from Costco and compare them to what we are using in this recipe. If you are feeling adventurous, you can play around with ratios or add new things I may not have included from the ingredients above. Just know you might get a completely different result.
Key Ingredients
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.
- Light 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
Here is how to make a copycat version of the Kirkland Signature marshmallow crispy cookies. Scroll down to the recipe card at the end of this post for full step-by-step instructions! If you’d rather skip the oven entirely, try my Crumbl Rice Krispies bar cookies, a marshmallow-and-cereal treat that comes together in minutes with no baking. My Ruffles Krispy treats swap in ridged potato chips for a sweet-and-salty spin on the same idea.
- Melt your butter in a light-colored saucepan over medium heat. Stir constantly. Watch for it to foam, then 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.
- In a mixing bowl, beat together the browned butter, shortening, light brown sugar, and granulated sugar until light and fluffy.
- Mix in the corn syrup, egg, egg yolk, and vanilla until smooth and fully combined.
- In a separate bowl, whisk together the flour, cornstarch, baking soda, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients and mix until just combined, without overworking the dough.
- Gently fold in the Rice Krispies and some of the mini marshmallows. Chill the marshmallows so they don’t melt into goo too early.
- Cover the brown butter dough and refrigerate for 1 hour. This step helps the cookies hold their shape, keeps the marshmallows from oozing too much, and prevents excessive spreading.
- Preheat your oven and line a cookie sheet with parchment. Scoop out roughly 3-tablespoon portions and leave plenty of space between them. Bake in the preheated oven until the edges are golden, but the centers are still slightly underbaked.
- As soon as the cookies come out of the oven, use a larger cookie cutter than the cookies to swirl them around (see the photos below) so they are a perfect circle and keep any marshmallow that oozed out inside.
- 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.
- 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.
Expert Tips
- Brown the butter in a light-colored pan. You can actually see when it hits that perfect golden stage without burning. Once you’ve got the hang of it, put it to use again in these peanut butter rice Krispy treats with marshmallows, where browned butter adds the same nutty depth to a classic no-bake treat.
- Let the browned butter cool. Hot butter melts the sugar instead of creaming with it and gives you flat, greasy cookies. Wait until it’s slightly thickened before mixing.
- Don’t skip the chill. An hour in the fridge keeps the marshmallows from oozing and the cookies from spreading. Chilling overnight gives you even thicker cookies with more flavor.
- Don’t overbake. Pull them when the edges are golden but the centers still look slightly soft. They finish setting on the hot baking sheet.
- Swirl them while they’re hot. Right out of the oven, swirl a cookie cutter slightly bigger than each cookie around it. It rounds them into perfect circles and tucks any escaped marshmallow back in.
- Save marshmallows for the tops. Halve a few mini marshmallows and press them onto the hot cookies for that signature Costco look!!
- Want them extra soft? Swap the granulated sugar for all brown sugar. It adds moisture and a deeper caramel flavor.
- Weigh your ingredients. A kitchen scale is way more accurate than measuring cups, especially for the flour.
Why This Recipe Works
- This recipe is perfect for people who aren’t Costco customers or don’t have a local store nearby.
- If you’re already a fan of the cookies but don’t want a huge 24-count container or want smaller cookies, this recipe is for you.
- The texture is absolute perfection, with soft, gooey marshmallow and crispy cereal combined into an ultra-chewy cookie.
- These unique cookies are a great choice for parties, baked goods sales, or an indulgent snack at home.
- They don’t use the usual preservatives that you find at industrial bakeries. For another easy Crumbl-inspired treat to add to your rotation, try these caramel apple Crumbl cookies, the same copycat-bakery magic with a fall twist.
Costco Marshmallow Crispy Cookies FAQs
Absolutely! Smaller Costco marshmallow crispy cookies bake a little faster, so watch them closely and pull them when the edges are golden but the centers still look soft.
Yes! Scoop the Costco marshmallow crispy cookie dough into balls, freeze them on a baking sheet, then move them to a freezer bag once they’re solid. Bake them straight from frozen, adding 1 to 2 extra minutes.
You can, but Rice Krispies give Costco marshmallow crispy cookies the light crunch that balances the chewy marshmallows, and other cereals will change the texture. If you want to riff on the mix-ins, my peanut butter cornflake cookies use cornflakes for a different crunchy-chewy combo, and these strawberry Rice Krispy treats add freeze-dried strawberries for a fruity twist.
Keep leftover Costco marshmallow crispy cookies in an airtight container at room temperature for 3 days or in the fridge for 5 days. My secret for keeping them soft is adding a slice of bread or a tortilla to the container. My Nestle Toll House cookie bars store the same way, so it’s an easy trick to remember for both.
I haven’t tried it myself, but a 1:1 gluten-free flour blend in place of the all-purpose flour should work for Costco marshmallow crispy cookies. Bake times may change slightly depending on your blend, and use a cereal labeled gluten-free, since regular Rice Krispies contain malt.
More Krispy Treat Recipe Favorites
If you tried this Costco Marshmallow Crispy Cookies or any other recipe on my blog, please leave a 🌟 star rating and let me know how it goes in the comments! I love hearing from you!
Costco Marshmallow Crispy Cookies Copycat Recipe
Ingredients
- 7 tbsp unsalted butter will brown down to ~85 g
- 2 tbsp shortening room temperature
- 1/3 cup light brown sugar packed
- 1/3 cup granulated sugar
- 1 large egg room temperature
- 1 egg yolk room temperature
- 1 tsp vanilla extract
- 1 3/4 cup all-purpose flour
- 1/2 tsp cornstarch
- 1/2 tsp baking soda
- 1/4 tsp baking powder
- 1/2 tsp kosher salt
- 1 1/2 tbsp light corn syrup
- 2/3 cup mini marshmallows more to top the cookie with
- 1 1/2 cup Rice Krispies cereal
Instructions
- Melt the butter in a light-colored saucepan over medium heat, stirring constantly. Watch for foaming, then golden brown bits at the bottom.7 tbsp unsalted butter
- Pour into a heatproof bowl, scraping in all the browned bits. Cool until slightly thickened (~85 g).
- Beat together browned butter, shortening, brown sugar, and granulated sugar for 2–3 minutes until light and fluffy.2 tbsp shortening, 1/3 cup light brown sugar, 1/3 cup granulated sugar
- Beat in corn syrup, egg, egg yolk, and vanilla until smooth and glossy.1 large egg , 1 tsp vanilla extract, 1 1/2 tbsp light corn syrup, 1 egg yolk
- In a separate bowl, whisk together flour, cornstarch, baking soda, baking powder, and salt. Gradually mix into wet ingredients until just combined.1 3/4 cup all-purpose flour, 1/2 tsp cornstarch, 1/2 tsp baking soda, 1/4 tsp baking powder, 1/2 tsp kosher salt
- Gently fold in Rice Krispies, and marshmallows.2/3 cup mini marshmallows, 1 1/2 cup Rice Krispies cereal
- Cover and chill 1 hour. This helps marshmallows not ooze too much and prevents excess spreading.
- Preheat oven to 350F and line a baking sheet with parchment.
- Scoop 3 Tbsp portions and space well apart. Bake 13-15 minutes until edges are golden but centers still slightly underbaked.
- 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 so that they are a perfect circle and keep any marshmallow that could've oozed out inside
- .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.
- Let cookies rest on the baking sheet for 10 min before transferring to a wire rack. Marshmallows will set as they cool.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
I’m thinking about adding peanut butter to the cookies! What do you think would be the best way to do that?
Great idea! I’d reduce the shortening to 1 tablespoon and add 2-3 tablespoons of creamy peanut butter in its place when you cream together the fats and sugars.
I’d recommend baking one test cookie first to see how the spread goes, then adjust from there if needed. Peanut butter can make cookies spread more, so definitely don’t skip the chilling step!
Let me know how they turn out!
I’m confused…what is these measures mean? 2 & 1.5 cups flour & 2 & 1 cup Rice Krispie mean?
That’s because the recipe is doubled (‘x2’ button on the recipe card), and the measurements just multiply by what’s written in the standard one serving recipe. So because the normal recipe amount is 1 and 3/4 cups for flour and 1 and 1/2 cups for rice krispies, it just doubles each part individually. So to find the amount, you would just add it up as normal. So 2 and 1.5 cups of flour is 3.5 cups, and 2 and 1 cup rice krispies is 3 cups.
The recipe says 1/3 g for the sugars. Does that mean 1/3 cup?
Yes you are correct thank you for catching that. Typo has been fixed 🙂
I love the use of brown butter in this cookie recipe! Also the fact that it doesn’t use super hard to get ingredient is a huge perk. Got everything from Walmart and it turned out delicious.
Thank you so much for giving these a shot and leaving a nice review 🙂 I’m so glad you liked them!