Preheat oven to 350°F. Stir together cookie mix, egg and butter until dough forms. Cover and refrigerate dough for 15 minutes.
Transfer dough to greased or floured surface and roll to ¼” thickness.
Cut to desired shapes with small cookie cutters. Place 1 inch apart onto greased or parchment lined cookie sheet. Bake 7-8 minutes. Let cookies cool an additional 2 minutes on pan. Transfer to a baking rack to cool completely.
Pair 2 gingerbread cookies together. I used a mini gingerbread cookie cutter (2 1/2” tall) and yielded 66 cookies total, or 33 pairs.
Mix together all ingredients for the spiced marshmallow buttercream until light and fluffy.
Transfer to a plastic bag and cut the corner to pipe frosting onto the inside of one of the gingerbread cookie pairs. Top with remaining cookie to make a sandwich.
Sprinkle colored sugar on outside of the buttercream edge. Finish by making buttons and face with piped icing and sugar pearls.
Icing- whisk together ½ cup powdered sugar, 1 teaspoon corn syrup and 1 teaspoon hot water. Transfer into plastic bag and cut a small corner to pipe frosting onto the cookies.