Step 1

Preheat the oven to 350°F. Line two large baking sheets with parchment paper and set aside.

Step 2

In a stand mixer or large mixing bowl with an electric hand mixer, cream the softened butter, granulated sugar, and brown sugar for 1-2 minutes, or until it becomes light and fluffy.

Step 3

Add the egg and vanilla extract. Beat until smooth and evenly combined, scraping the sides of the bowl as necessary.

Step 4

With the mixer off, add the flour, baking soda, baking powder, and salt. Mix on low-speed until just combined. Be very careful not to over-mix the dough!

Step 5

Use a rubber spatula to gently fold in about one cup of the Lucky Charms marshmallows. Mix until the marshmallows are just combined into the dough, but be careful not to crush them too much.

Step 6

Use a cookie scoop to form evenly sized balls of cookie dough (about 1.5 tablespoons per ball). Place on the baking sheet with 2-3 inches between each cookie to allow for spreading.

Step 7

Bake for 10-11 minutes, or until the edges of the cookies are just set and very lightly golden. Remove from the oven and immediately press additional Lucky Charms marshmallows into the top of each cookie for a pretty appearance.

Step 8

Allow the cookies to cool on the baking sheet for 5-10 minutes to finish setting up. Then, transfer to a cooling rack to cool completely. Enjoy!