01 - Preheat oven to 350°F and line two baking sheets with parchment paper.
02 - Whisk together flour, baking soda, and salt in a medium bowl. Set aside.
03 - Beat butter, granulated sugar, and brown sugar in a large bowl until light and fluffy, approximately 2–3 minutes.
04 - Beat in eggs one at a time, then incorporate peppermint and vanilla extracts.
05 - Gradually add green food coloring, mixing until the desired shade is achieved.
06 - Mix in dry ingredients on low speed until just combined.
07 - Gently fold in chocolate chips and chopped mint chocolate pieces if using.
08 - Drop rounded tablespoons of dough onto prepared baking sheets, spacing 2 inches apart.
09 - Bake for 9–11 minutes until edges are set but centers remain soft.
10 - Let cookies rest on baking sheets for 5 minutes, then transfer to a wire rack to cool completely.