Preheat the oven to 350 F. In a large bowl, whisk together cake mix, eggs, and vegetable oil until smooth. Fold in the lucky charms cereal.
Use a cookie scoop to place the cookies onto a large ungreased baking sheet at least 2-inches apart. Bake for 10-12 minutes. Remove half of the cookies from the baking sheet.
Place one marshmallow along with some chocolate chips onto each cookie on the baking sheet. Bake for 2-3 minutes. Remove from the oven, and sandwich with the remaining cookies.