01 - Preheat your oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together flour, baking soda, and salt. Set aside.
03 - In a large bowl, cream the butter, granulated sugar, and brown sugar until light and fluffy, about 2 to 3 minutes.
04 - Beat in eggs one at a time, then add peppermint and vanilla extracts.
05 - Add green food coloring gradually until desired shade is achieved.
06 - Mix in the dry ingredients on low speed until just combined.
07 - Fold in chocolate chips and chopped mint chocolate pieces if using.
08 - Scoop rounded tablespoons of dough onto prepared baking sheets, spacing 2 inches apart.
09 - Bake for 9 to 11 minutes, until edges are set but centers are still soft.
10 - Let cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.