01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together flour, baking soda, and salt in a medium bowl.
03 - Beat softened butter with granulated sugar and brown sugar until light and fluffy, about 2 to 3 minutes.
04 - Add eggs one at a time, mixing well after each addition. Blend in vanilla and peppermint extracts.
05 - Gradually add dry ingredients to wet mixture, mixing until just incorporated.
06 - Fold in semisweet chocolate chips, white chocolate chips if using, chopped mint, and crushed peppermint candies.
07 - Scoop tablespoon-sized portions of dough onto prepared sheets, spacing them about 2 inches apart.
08 - Bake for 9 to 11 minutes, until edges are lightly golden and centers remain soft.
09 - Allow cookies to cool on baking sheets for 5 minutes, then transfer to wire racks to cool completely.