Rainbow Lucky Charms Marshmallow Stuffed Cookies

Rainbow Lucky Charms Marshmallow Stuffed Cookies

These Rainbow Lucky Charms Marshmallow Stuffed Cookies have got to be the funnest cookies I’ve ever created! Don’t get me wrong, I can party hard with a classic chewy chocolate chip cookie for sure, but LOOK AT THESE! It’s no secret that I love a bold splash of color! I add sprinkles to my pie dough for goodness sake! So when I was thinking up the perfect treat for celebrating St. Patrick’s Day with (or ANY DAY, let’s be honest) I was so excited that these came to my mind!

The cookie is a beautiful classic chewy sugar cookie base with crushed cereal in the dough, simply colored with a few drops of food coloring gel! Feel free to try using natural food coloring with these as well! The cookies are then stuffed with jumbo marshmallows, rolled in cereal sugar, and baked to perfection!

Rainbow Lucky Charms Marshmallow Stuffed Cookies Scoops
Rainbow Lucky Charms Marshmallow Stuffed Cookies

Tips for Making the Best Cookies

  • USE A SCALE: My number one tip for baking anything in general is to use a scale to measure out your ingredients! Not only will this make for less dirty dishes, but it will make sure that you’re using the correct amount of ingredients at every step, which will ensure your bakes turn out exactly as the author intended them to! With cookies, though, measuring the amount of flour is usually the most important factor for your cookies turning out exactly as they should! The usual culprit to cookies that don’t spread well or don’t end up perfectly chewy is TOO MUCH FLOUR. If you’re still using a measuring cup for your flour, consider switching to a scale instead. If you’re still not convinced, then at least look up the “scoop and level” technique.
  • Don’t Over Mix the Dough: the most fabulous cookies are slightly crispy on the edges, and perfectly soft and chewy in the middle. To achieve the best cookie texture, don’t over mix your dough once you’ve added your dry ingredients. I like to mix just until the dry ingredients are incorporated.
  • Chill the Cookie Dough: I know you don’t want to wait, but trust me, chilling the cookie dough in the fridge is one of the best things you can do as far as TASTE and TEXTURE of your cookies! And you don’t even have to do anything! I love chilling my cookie dough overnight in the fridge for those benefits but ALSO because it will allow me to split up my work! Prepare the dough and clean up on day 1, then assemble and bake on day 2!
Rainbow Lucky Charms Marshmallow Stuffed Cookies

How Do I Stop Marshmallow from Disappearing in My Cookie?

With marshmallow stuffed cookies, I’ve often found that I’ll go to rip open a cookie, expecting there to be beautifully melted marshmallow fluff on the inside, just to find that it’s all disappeared! What happened?

If the marshmallow is perfectly covered up and in the very center of the cookie, I’ve found that it has a 50/50 chance of surviving. It might all melt away, baking WITH the cookie dough, or it might find an escape route under the cookie and seep out that way! It will caramelize and leave only a tiny trace that it was in there! Although this in no way ruins the cookies (they’ll still be delicious!), it can be a little disappointing.

For these Rainbow Lucky Charms Marshmallow Stuffed Cookies, to make sure the marshmallow has the highest chance of sticking around, is to make sure when you’re assembling the cookies and closing the marshmallow inside, leave some of the marshmallow exposed on top, and keep this part facing UP when baking!

Make-Ahead Tips

Prep dough and chill in fridge: a day or two before you want to bake these off, you can prep the dough, color them, and scoop them out, placed evenly onto a baking sheet, covered tightly with plastic and kept in the fridge overnight! Assemble and bake the next morning.

Prep dough, assemble, and FREEZE: You can definitely freeze assembled cookies for future baking! Just place assembled cookies evenly on a parchment lined baking sheet and freeze until solid. Place all dough balls into a freezer zip lock bag. When you want to bake cookies, remove the balls from freezer and let them thaw a bit while you preheat the oven. Bake as instructed below, adding 1-2 additional minutes.

Equipment Needed

Ingredients for Rainbow Lucky Charms Marshmallow Stuffed Cookies

  • All purpose flour
  • Baking soda
  • Kosher salt
  • Lucky Charms Cereal
  • Unsalted butter
  • Granulated Sugar
  • Light or Dark Brown Sugar
  • Egg
  • Pure vanilla extract
  • Food coloring gel
  • Jumbo marshmallows

How To Make Rainbow Lucky Charms Marshmallow Stuffed Cookies

  • Whisk together dry ingredients
  • Cream together butter and sugars until fluffy and light. Add dry ingredients.
  • Split into 4 equal portions and mix in colors.
  • Scoop out 1 tablespoon portions for all cookie dough. Chill in fridge.
  • Assemble cookies by combining 1 scoop of each color, then creating a big crater into the ball, stuffing with a half of a jumbo marshmallow, and rolling in cereal sugar.
  • Bake!

Other Recipes You’ll Love!
Raspberry Pistachio with Matcha Marbled Cookies
Nutella Stuffed Chocolate Chip Cookies
Peanut Butter Marshmallow Chocolate Chip Cookies

Rainbow Lucky Charms Marshmallow Stuffed Cookies
Yield: 14-16 cookies

Rainbow Lucky Charms Marshmallow Stuffed Cookies

Prep Time: 45 minutes
Cook Time: 20 minutes
Total Time: 1 hour 5 minutes

These super fun and festive Rainbow Lucky Charms Marshmallow Stuffed Cookies are the perfect treat for celebrating St. Patrick's Day-- or any day, really! They're chewy and perfectly sweet, with fun melty marshmallow surprise inside!


  • 2 1/4 cup (290g) all purpose flour
  • 1 tsp baking soda
  • 1 tsp kosher salt
  • 1 cup (40g) Lucky Charms Cereal (separated from marshmallows), finely crushed (some bigger pieces is ok)
  • 1 cup (2 sticks, 227g) unsalted butter, room temp
  • 1 cup (200g) granulated sugar
  • 1/3 cup (66g) light or dark brown sugar
  • 1 large egg
  • 2 tsp pure vanilla extract
  • Pink, blue, and green food coloring gel for coloring cookie dough
  • 8-10 Jumbo marshmallows, cut in half (DON'T USE MINI MARSHMALLOWS)

Cereal Sugar Coating

  • 1/2 cup (20g) Lucky Charms cereal, finely crushed
  • 1/2 cup (100g) granulated sugar for coating


Cookie Dough

  1. In a medium bowl, whisk together flour, baking soda, salt, and 40 grams of crushed cereal. Set aside
  2. In the bowl of a stand mixer, cream together butter and sugars until combined and fluffy, about 3-5 minutes on high. Beat in the egg and vanilla extract. With the mixer on low speed, add the flour mixture until just combined. Split the cookie dough into 4 equal portions.
  3. Leave one portion uncolored, covered. Add a few drops of food coloring gel to the other 3 portions and mix in well. Scoop out all the cookie dough in 1 tablespoon-portions onto a parchment lined baking sheet. Place entire tray into fridge, covered, to chill for at least 20 minutes or overnight.

Assemble Cookies and Bake

  1. While cookie dough balls are chilling in the fridge, PREHEAT oven to 350°F.
  2. In a medium bowl, combine crushed Lucky Charms and granulated sugar for the cereal sugar coating. Set aside.
  3. To assemble cookies, take one scoop of each cookie dough color and smoosh them together to form a ball. With the ball in the palm of one hand, use your other thumb to push a large, deep crater into the middle of it. Place half a jumbo marshmallow into the middle and close up the cookie dough ball, leaving some of the marshmallow revealed (this will help it to not completely melt away during the baking process).
  4. Roll entire dough ball into cereal sugar coating and place 1 or 2 cute Lucky Charms Marshmallows on top. Place dough balls onto a large parchment lined baking sheet 2-3 inches apart, with the revealed marshmallow facing UP.
  5. Bake for 8 minutes, then bang the bottom of the baking sheet on the baking rack, turn the pan, and bake for an additional 6 minutes. Let cookies cool for 10 minutes on the baking sheet before removing and ENJOY!

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