Preheat the oven: Preheat your oven to 350°F (175°C). Line a cookie sheet with parchment paper so the cookies don’t stick and set it aside while you prepare the cookie dough.
Cream the butter and sugar: In a medium bowl, beat the butter and brown sugar with a hand mixer until smooth and well combined. This step helps create soft and flavorful Lucky Charms cookies.
Add the egg: Add the egg to the sugar mixture and beat again until fully incorporated. The mixture should look creamy and smooth.
Mix the dry ingredients: In a small bowl, whisk together the flour and baking powder. This helps evenly distribute the leavening, so the cookies bake properly.
Combine the dough: Gradually add the dry ingredients into the wet mixture and mix until a soft cookie dough forms. Be careful not to overmix.
Add the Lucky Charms: Gently fold in the Lucky Charms marshmallow bits. Scoop the dough and roll it into 1-inch balls, then place them on the prepared cookie sheet.
Bake the cookies: Bake the lucky charms cookies for about 12 minutes, or until the edges turn light golden brown.
Add extra marshmallows: Once you remove the cookies from the oven, press a few extra marshmallow bits or Lucky Charms marshmallow pieces on top while they are still warm. This gives the cookies a colorful finish and extra cereal flavor.
Serve and enjoy!