Preheat the oven to 350 degrees. Line your baking sheet(s) with parchment paper and set aside.
Add in the chocolate chips and the marshmallows. Mix well. If your mixer is struggling, mix by hand until the chips and marshmallows are thoroughly combined.
Bake for about 9-11 minutes or until the edges are set and the center is no longer shiny. Allow to cool completely on a wire rack.
Storage: Cookies can be stored in an airtight container for about one week or frozen for 3 months.