01 - Set the oven to 350°F and line two baking sheets with parchment paper.
02 - Whisk together the flour, baking soda, and salt in a medium bowl until evenly mixed.
03 - Beat the softened butter and granulated sugar in a large bowl using an electric mixer or whisk until light and fluffy, about 2 to 3 minutes.
04 - Add the egg, vanilla extract, and peppermint extract to the creamed mixture, beating until fully combined.
05 - Gradually fold the dry ingredient mixture into the wet ingredients just until combined, avoiding overmixing.
06 - Gently fold in the crushed peppermint candies and white chocolate chips if desired.
07 - Scoop tablespoon-sized portions of dough onto the prepared baking sheets, spacing them approximately 2 inches apart.
08 - Bake in the preheated oven for 10 to 12 minutes, or until the cookie edges turn lightly golden and the centers are set.
09 - Allow the cookies to cool on the baking sheets for 5 minutes before transferring to a cooling rack to cool completely.