01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.
03 - In a large mixing bowl, cream the softened butter, granulated sugar, and brown sugar together until light and fluffy, about 2–3 minutes.
04 - Beat in the eggs one at a time, then add the vanilla extract and mint extract, mixing until combined.
05 - Add green gel food coloring, starting with 1/4 teaspoon and increasing as needed to reach your desired shade of green. Mix until evenly colored.
06 - Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined.
07 - Fold in the chocolate chips and chopped dark chocolate if using.
08 - Scoop tablespoon-sized balls of dough onto the prepared baking sheets, spacing them about 2 inches apart.
09 - Bake for 10–12 minutes, or until the edges are set and the centers are just barely golden.
10 - Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.