1. Line a large cookie sheet with parchment paper.
2. Beat the butter and powdered sugar until light and fluffy.
3. Mix in flour, salt, and mint extract.
4. Add green food coloring and chocolate chips.
5. Form dough into balls and refrigerate.
6. Preheat oven to 375°F.
7. Bake cookies for 7-8 minutes until lightly browned.
8. Cool on sheet, then dust with powdered sugar.
9. Dust a baking sheet with powdered sugar. Place cookies on it and dust with more powdered sugar until coated. Let cool completely.