Melt two sticks of butter (1 cup) in the microwave. Combine melted butter and cocoa powder in a large mixing bowl or bowl of a stand mixer. Stir until smooth.

Mix brown sugar and white sugar with the butter/cocoa mixture.

Add eggs and vanilla.

Mix in salt, baking soda, and flour.

Cover bowl with plastic and chill dough for 45 minutes- 1 hour. Preheat oven to 350 degrees.

Scoop dough onto parchment paper lined cookie sheets using a medium cookie scoop (2 Tbsp. size).

Bake cookies for 10 minutes. While cookies bake cut marshmallows in half with scissors.Place a marshmallow half (sticky side down) onto each hot cookie. Place cookies back in the oven and bake an additional 2-3 minutes (marshmallows should be slightly puffed). DO NOT OVERBAKE MARSHMALLOWS.

Press each marshmallow down with the back of a spoon.

Let cool on a cookie sheet for a few minutes then transfer to a wire rack to cool completely.

Heat glaze ingredients in a microwave-safe bowl for 30 seconds. Stir. Heat for an additional 15-20 seconds. Stir until smooth and creamy. If additional time is needed do it in 10-second increments. Note: You can use a double boiler or small saucepan over the stove to melt the chocolate and glaze instead of a microwave if you want. Drizzle glaze over cookies. Add sprinkles, if desired. Allow glaze to set up (placing cookies back into the refrigerator for 15-20 minutes will speed this up).Cookies can be enjoyed chilled or at room temperature.