Preheat the oven to 375°F. Line a baking sheet with parchment paper, set aside.

In a medium-sized bowl, whisk to combine the flour, baking soda, and salt. Set aside.

In a large bowl, add the browned butter and both sugar. Mix until combined.

Add in the egg, egg yolk, and vanilla extract. Beat on low speed until fluffy.

Mix in the dry ingredients slowly, until the dough comes together. Do not over mix the dough.

Fold in the chocolate chips using a spatula. Cover the bowl with plastic wrap and chill in the refrigerator for at least 30 minutes, or overnight.

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 stuffed cookie dough balls on the lined baking pan around 2 inches apart. They will spread as they cook, so keep that in mind.

Bake for 8 minutes, or until the edges look slightly golden. Remove the cookies 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 2 minutes. Do not over bake the cookies. It is better that they are a bit under-baked than overbaked!

Let them cool for 5 minutes on the baking sheet before moving them to a cooling rack to cool completely.