Preheat the oven to 375 degrees F. Line a baking pan with parchment paper and set aside.
Brown the butter over medium heat. Stir constantly until it turns golden brown. Do NOT leave it on the stove, because it can easily get burned. Once it is ready, let it cool.
In a large bowl, add the butter and both sugars. Mix until combined.
Add the eggs and vanilla. Beat on LOW until fluffy.
Mix in the dry ingredients slowly, until just combined. Make sure to not over mix or your cookies will not be soft.
Use a spatula to fold in the chocolate chips.
Cover the bowl with plastic wrap and chill in the refrigerator for 1 hour.
Use a small cookie scoop to make the balls of dough. Place your thumb in the middle to form a cavity and place 2 mini marshmallows inside. Roll together until marshmallows are completely covered.
Place them on the lined baking pan around 2 inches apart. They will expand, so keep that in mind.
Bake for 8 minutes or until the edges look lightly golden, remove from the oven and gently press 1 or 2 more mini marshmallows into the top of each cookie. Place the cookies back in the oven for another minute or two.