Preheat your oven to 350°F (175°C) and prepare a baking sheet with parchment paper.

In a medium mixing bowl, whisk together the all-purpose flour, baking soda, and salt.

In a large mixing bowl, beat together the softened unsalted butter, brown sugar, and granulated sugar until light and fluffy.

Add the egg and vanilla extract to the creamed mixture and mix until smooth.

Gradually add the dry ingredient mixture to the wet mixture, mixing until just combined.

Gently fold in the dark chocolate chips, white chocolate chips, and crushed peppermint candy.

Using a cookie scoop, drop rounded tablespoons of dough onto the prepared baking sheet.

Bake for 10-12 minutes or until the edges are golden brown, then cool on the baking sheet for 5 minutes before transferring to a wire rack.