Name: Marshmallow Crispy Cookies (Costco Copycat) Recipe
Prep time: 15 min
Cook time: 13 min
Total time: 36 min
Cuisine: American
Ingredients: ½ cup salted butter; 1 large egg (room temperature); 1 teaspoon vanilla extract or vanilla paste; ¾ cup brown sugar; ½ cup granulated sugar; ⅔ teaspoon baking soda; ¾ teaspoon salt; 1 cup + 2 tablespoons all-purpose flour; 1½ cups rice krispie cereal; ⅔ cup mini marshmallows; Flaked salt for sprinkling

Jump to Recipe

Picture this: the warm, nutty aroma of browned butter filling your kitchen, mingling with the sweet scent of toasty marshmallows and crisped rice cereal. As you bite into these Marshmallow Crispy Cookies (Costco Copycat) Recipe delights, your taste buds dance with the perfect balance of chewy, crispy, and melty textures all at once. These cookies are not just a treat; they’re a nostalgic hug from your oven, a quick little magic that impresses every time you pull them out, perfect for sharing or sneakily enjoying by yourself.

Why You’ll Love This Marshmallow Crispy Cookies (Costco Copycat) Recipe

Ready in 36 minutes: From start to finish, these cookies come together fast, perfect for those sudden sweet cravings or last-minute gatherings.
Uses simple ingredients: Pantry staples like butter, brown sugar, rice krispie cereal, and mini marshmallows create magic with no fuss.
Perfect for beginners: No complicated techniques—just browning butter, mixing, folding, and baking with confidence.
Impressive presentation: The sprinkle of flaky sea salt on top contrasts beautifully with the golden cookie edges, making these irresistibly photogenic.
Customizable: Add your favorite mix-ins or swap ingredients to make them your own sweet masterpiece.

Why This Marshmallow Crispy Cookies (Costco Copycat) Recipe Works

This recipe shines thanks to a few key details that elevate it beyond ordinary cookies. First, browning the butter creates a rich, nutty flavor that infuses every bite, lending depth and warmth. Next, folding in the rice krispie cereal right before baking preserves that crisp crunch, perfectly offsetting the chewy delight of mini marshmallows melting inside. Finally, a light sprinkle of flaky sea salt enhances and balances the sweetness, making these cookies addictive and utterly crave-worthy.

A close-up view of freshly baked cookies arranged in three vertical rows on white parchment paper, placed on a dark brown baking tray with visible wear marks on the right edge. Each cookie is golden brown with a slightly uneven surface and a rough texture showing small oat flakes. White melted marshmallow spots are scattered throughout the cookies, giving a soft, puffy effect. There are small flakes of salt sprinkled on top, adding a contrasting white sparkle on the warm cookie surface. The background beyond the baking tray shows a white marbled texture. photo taken with an iphone --v 7

Ingredients You’ll Need

With just a handful of straightforward ingredients, you’ll be amazed at how they come together to create big flavor and texture in these cookies.

Salted butter: The base for rich flavor, browned for that irresistible toasty note.
Brown sugar: Adds moistness and deep caramel sweetness.
Granulated sugar: Balances sweetness and helps with cookie structure.
Egg: Binds everything together and helps create the chewy texture.
Vanilla extract or vanilla paste: Brings warm, sweet aromatic depth.
Baking soda: Lightens the dough and helps cookies spread just right.
Salt: Enhances all flavors and prevents flat sweetness.
All-purpose flour: The sturdy canvas that holds the cookie structure.
Rice krispie cereal: The secret to that addictive crispy crunch.
Mini marshmallows: Melt into gooey pockets of sweet bliss.
Flaked sea salt: A finishing touch that intensifies flavor and adds a subtle crunch.

Ingredient Substitutions & Tips

Salted butter: Use unsalted butter plus a pinch of salt if needed.
Vanilla paste: Pure vanilla extract or vanilla bean powder works beautifully as well.
Rice krispie cereal: Substitute with any similar crispy cereal, like corn flakes or even crushed pretzels for a savory twist.
Mini marshmallows: Regular marshmallows cut into smaller pieces can be used if mini aren’t available.

👨‍🍳 Pro Tips for Perfect Results

Brown the butter carefully: Keep stirring and watch closely; the line between browned and burnt is thin but critical for flavor.
Chill the dough for 10 minutes: This helps the cookies hold their shape and develop a better texture.
Don’t overmix flour: Mix until just combined to keep the cookies tender, not tough.
Use a cookie scoop: A 3-tablespoon scoop helps create evenly sized cookies that bake uniformly.
Space cookies generously: They spread thin, so leave plenty of room on your baking sheet.

How to Make Marshmallow Crispy Cookies (Costco Copycat) Recipe

Step 1: Preheat and Prepare

Start by heating your oven to 350 degrees Fahrenheit and lining a baking sheet with parchment paper. This ensures your cookies bake evenly and won’t stick, making clean-up a breeze.

💡 Pro Tip: Use fresh parchment paper for each batch to avoid any burnt bits sticking to your cookies.

Step 2: Brown the Butter

In a medium saucepan over medium heat, melt ½ cup of salted butter. Keep stirring beyond melting as the butter foams and then begins to turn golden brown, releasing a warm, nutty aroma. Watch closely to avoid burning. Once browned, pour into a bowl and chill in the fridge or freezer for about 10 minutes until slightly cool but still liquid.

💡 Pro Tip: Use a light-colored pan to better monitor the butter’s color change.

Step 3: Mix Sugars and Egg

In a mixing bowl, combine the cooled brown butter with ¾ cup brown sugar and ½ cup granulated sugar. Add one large egg and 1 teaspoon vanilla paste or extract, mixing on low speed for about 30 seconds until smooth and glossy.

💡 Pro Tip: Room temperature egg blends more easily for silky dough.

Step 4: Add Dry Ingredients

Gently fold in ¾ teaspoon salt, ½ teaspoon baking soda, and 1 cup plus 2 tablespoons all-purpose flour. Be careful not to overmix; stop once combined to keep your cookies tender.

💡 Pro Tip: Sift your flour in with the baking soda to ensure an even mix.

Step 5: Fold in Cereal and Marshmallows

Carefully fold in 1½ cups rice krispie cereal, followed by ⅔ cup mini marshmallows, distributing them evenly but gently so marshmallows don’t melt into the dough prematurely.

💡 Pro Tip: Add marshmallows last to preserve their shape and texture during baking.

Step 6: Scoop and Bake

Using a 3-tablespoon cookie scoop, portion large dough balls onto your cookie sheets, spacing 4–5 cookies per sheet to allow room for spreading. Bake for 10 to 13 minutes until edges are a light golden brown but centers still look soft. Remove from oven and sprinkle with flaky sea salt immediately.

💡 Pro Tip: Pull the cookies out right as edges brown to keep that perfect chewy center.

Common Mistakes to Avoid

Learn from these common pitfalls:

Burning the butter: Leaving the butter unattended during browning can cause a burnt flavor and ruin the base.
Overmixing the dough: It results in dense, tough cookies instead of tender and chewy.
Using cold eggs: This can cause the dough to curdle or not blend smoothly.
Underestimating cookie spread: Not spacing the dough balls well can cause cookies to merge into one large sheet.
Overbaking: Cookies left in too long become dry, losing their signature chewy texture.
Skipping the salt topping: The flaky salt creates a crucial contrast that lifts all the flavors.

Delicious Variations to Try

Once you’ve mastered the Marshmallow Crispy Cookies (Costco Copycat) Recipe, why not experiment?

Chocolate Chip Marshmallow Crispy

Add ½ cup of your favorite chocolate chips for a melty chocolate surprise in every bite.

Peanut Butter Twist

Mix in ¼ cup of creamy peanut butter into the dough for a rich, nutty flavor that pairs perfectly with marshmallows.

White Chocolate and Cranberry

Swap mini marshmallows for dried cranberries and add white chocolate chunks for a festive, tart-and-sweet combo.

Toasted Coconut Crunch

Fold in ½ cup toasted shredded coconut along with your rice krispies for an island-inspired flair.

Salted Caramel Drizzle

Once cooled, drizzle a bit of warm salted caramel sauce over the cookies for an extra decadent touch.

How to Serve Marshmallow Crispy Cookies (Costco Copycat) Recipe

A close-up view of a single round cookie broken in half, placed on a white marbled surface. The cookie has a golden-brown color with a slightly crisp edge and a chewy, textured center that contains visible sugar crystals on top. Between the two halves, there are stretchy, melted white marshmallow strands connecting them, creating a gooey effect. The surface of the cookie shows a soft, chewy texture with some browned spots from baking. photo taken with an iphone --v 7

Garnishes

Sprinkle extra flaky sea salt or dust with a light coating of powdered sugar for a pretty presentation. You can also top with a tiny marshmallow toasted lightly with a kitchen torch for that campfire vibe.

Side Dishes

Pair these cookies with a cold glass of milk, a creamy latte, or a rich hot chocolate for a cozy treat time.

Creative Ways to Present

Stack them in a clear jar tied with a ribbon as a gift, or create individual cookie sandwiches filled with marshmallow or chocolate ganache for an elevated dessert.

Make Ahead and Storage

Storing Leftovers

Keep your cookies fresh in an airtight container at room temperature for up to 3 days to preserve their chewy and crispy texture.

Freezing

Freeze baked cookies in a single layer on a baking sheet, then transfer to a zip-top bag or container. They’ll keep well for up to 2 months. Thaw at room temperature before enjoying.

Reheating

Warm cookies briefly in the microwave for 10-15 seconds or in a low oven to revive that freshly baked softness and gooey marshmallow delight.

FAQs

Can I make these cookies gluten-free?

Yes! Substitute your all-purpose flour with a gluten-free 1-to-1 baking flour blend and double-check your rice krispies are gluten-free.

Why do I need to brown the butter? Can I skip it?

Browning the butter adds a delicious nutty flavor and complexity that plain melted butter doesn’t provide. Skipping it will give a less intense flavor.

Can I use regular-size marshmallows instead of mini?

You can, but cut them into smaller pieces so they distribute evenly without clumping.

How should I store the cookie dough if I want to bake later?

Wrap tightly and refrigerate for up to 24 hours, or freeze for up to a month. Let thaw and bring to room temperature before baking.

Can I add nuts or chocolate chips?

Absolutely! Chopped nuts or chocolate chips enhance both texture and flavor if you want to mix things up.

Why are my cookies turning out flat?

Make sure the dough is chilled briefly before baking and avoid too much butter melting out by not overbaking.

Is it necessary to use flaky sea salt on top?

While optional, flaky salt creates a stunning flavor contrast that takes these cookies to the next level.

Can I make these cookies vegan?

It’s a bit tricky because of butter and egg, but you can experiment with vegan butter and flax eggs. Texture and flavor may vary.

Final Thoughts

These Marshmallow Crispy Cookies (Costco Copycat) Recipe truly capture the magic of sweet comfort food with simple ingredients and a few expert touches. Each bite brings a symphony of textures—from chewy centers and crispy cereal to gooey marshmallow pockets topped with just the right hint of salty crunch. Whether you’re making these for a cozy night in, a crowd-pleasing party treat, or to satisfy a nostalgic craving, they never disappoint.

Have you tried this Marshmallow Crispy Cookies (Costco Copycat) Recipe? I’d love to hear how it turned out! Leave a comment below. If you loved this recipe, please share it with friends and family. Happy cooking! 😊