Marshmallow Crispy Cookies Costco Copycat

By Lily | Last modified on Jan 27, 2026

Featured in: Desserts

Marshmallow Crispy Cookies (Costco Copycat)

Imagine biting into a cookie that’s wonderfully crispy on the outside with gooey mini marshmallows melting perfectly in every chewy bite. These Marshmallow Crispy Cookies bring a warm caramel undertone thanks to browned butter, layered with the nostalgic crunch of rice krispie cereal, evoking memories of cozy gatherings and sweet indulgence.

Inspired by Costco’s famous treat but crafted to elevate the flavors and freshness, this recipe offers a no-fuss, quick bake that delivers bakery-quality results at home without chilling the dough. You’ll be amazed at how effortlessly these cookies come together, making them perfect for last-minute cravings or sharing with loved ones.

Why You’ll Love This Recipe

Brown butter adds a rich, nutty caramel flavor that enhances every bite.
No need to chill the dough, allowing for quick prep and baking.
The combination of crispy rice cereal and chewy marshmallows creates a delightful texture contrast.
Simple ingredient list using pantry staples for easy accessibility.

Ingredients

Salted Butter (½ cup / 113.5 g): Provides a rich, creamy base and becomes caramelized for deep flavor during browning.
Brown Sugar (¾ cup / 165 g): Adds moisture and sweetness with a hint of molasses for a soft, chewy texture.
Granulated Sugar (½ cup / 100 g): Balances sweetness and helps create the perfectly crisp cookie edges.
Large Egg (1, room temperature): Binds ingredients and contributes to the cookie’s chewy interior.
Vanilla Extract or Paste (1 teaspoon): Enhances overall flavor with warm, aromatic notes.
Baking Soda (½ teaspoon): Acts as a leavening agent to slightly lift the cookies for the ideal texture.
Salt (¾ teaspoon): Balances the sweetness and intensifies other flavors.
All-Purpose Flour (1 cup + 2 tablespoons / 158 g): The foundation of the cookie structure; light and fluffy measurement is key.
Rice Krispie Cereal (1½ cups / 43 g): Adds a crispy, airy crunch that contrasts beautifully with the soft marshmallows.
Mini Marshmallows (⅔ cup / 30 g): Provides pockets of chewy, sticky sweetness throughout the cookie.
Flaked Salt (for topping): Sprinkled on top to enhance flavor and add a hint of savory crunch.

Instructions

Brown the Butter: Start with ½ cup of salted butter melted in a medium saucepan over medium heat. Continue cooking past melting until the butter foams and turns a rich golden brown with a nutty aroma. This step intensifies the flavor, adding a caramel-like depth that sets these cookies apart. Transfer it to a bowl and chill for 10 minutes to cool and slightly solidify.
Cream Brown Butter and Sugars: In a medium mixing bowl, combine the chilled brown butter and both sugars. Beat them together on low speed until the mixture is smooth and slightly lightened. This ensures even sweetness and creates a sticky, luscious base for your dough.
Add Egg and Vanilla: Beat in one large room temperature egg along with vanilla extract or vanilla paste. Mixing until well incorporated yields a smooth dough that will hold together while baking, enriching the flavor profile with warm vanilla notes.
Incorporate Dry Ingredients: Slowly add the salt, baking soda, and all-purpose flour to the wet mixture. Mix gently to combine, taking care not to overmix. Overmixing can develop gluten too much, leading to tougher cookies, so fold just until no flour streaks remain, preserving tenderness.
Fold in Rice Krispies and Mini Marshmallows: Carefully fold in 1½ cups of crispy rice cereal and ⅔ cup of mini marshmallows. The rice krispies add crunch while the marshmallows provide gooey softness, creating delightful texture contrast in every bite.
Scoop and Bake: Using a 3-tablespoon cookie scoop, portion the dough into large balls spaced widely on parchment-lined baking sheets (4-5 per sheet) because these cookies spread thin during baking. Bake at 350°F for 10-13 minutes until the edges turn light golden brown. Avoid overbaking to keep the centers chewy and moist.
Finish with Flaked Salt: Immediately after removing from the oven, sprinkle flaked salt over the warm cookies. The salt amplifies the sweetness and adds a sophisticated savory touch that balances each bite perfectly.

You Must Know

Adding two extra tablespoons of flour will yield thicker cookies if preferred.
Using kitchen scale for flour measurement improves consistency and texture.
Cookies spread thinly so ensure enough space on baking sheets during baking.
The browned butter process requires attention as it can burn quickly once the foaming subsides.

Storage Tips

Store cooled cookies in an airtight container at room temperature for up to 5 days. To maintain crisp edges and chewy centers, layer parchment paper between cookies. For longer storage, freeze for up to 2 months and thaw at room temperature before serving.

Serving Suggestions

Enjoy these cookies with a cold glass of milk, a cup of hot cocoa, or your favorite coffee for a comforting treat. They also pair beautifully with vanilla ice cream to create a dessert parfait that highlights their crispy and chewy texture duo.

Professional Tips

Use vanilla paste instead of extract for a richer vanilla flavor and visible vanilla flecks.
Chilling the browned butter enhances dough texture and prevents spreading.
Handling the dough gently preserves the crisp-chewy balance in the finished cookie.
Flaked sea salt finishing elevates flavor complexity and presentation.

FAQs

Can I use unsalted butter instead of salted?: Yes, but reduce added salt slightly to avoid over-seasoning. Adjust to taste as salted butter adds depth to flavor.
Why do these cookies spread so thin?: The browned butter and melted sugars cause the dough to spread during baking, creating a thin, crispy texture that’s signature to this cookie.
Can I substitute mini marshmallows with regular-sized marshmallows?: Mini marshmallows distribute more evenly and melt better. If using regular ones, chop into small pieces before folding into dough.
Do I need to chill the dough?: No chilling is required, but cooling the browned butter and dough briefly helps control spread and improves texture.
What is the best way to measure flour?: Use a kitchen scale for accuracy or spoon flour lightly into measuring cups without packing to avoid dense dough.
How long will cookies stay fresh?: Stored airtight at room temperature, they stay fresh for about 5 days. Freezing extends shelf life to 2 months.
Can I double this recipe?: Yes, double all ingredients and bake on multiple sheets. Make sure to have enough space for spreading cookies.