Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.
Cream together softened butter, granulated sugar, and brown sugar in a stand mixer until light and fluffy.
Incorporate the egg, peppermint extract, and vanilla extract into the butter mixture.
Whisk together flour, cocoa powder, espresso powder, baking soda, and salt in a separate bowl.
Gradually mix the dry ingredients into the wet ingredients until a cohesive dough forms.
Fold in the semi-sweet chocolate chips.
Scoop 1.5-tablespoon portions of dough onto the prepared baking sheets, spaced 2 inches apart.
Bake for 10 to 12 minutes until edges are set but centers remain slightly soft.
Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.
Drizzle cooled cookies with melted white chocolate and immediately garnish with crushed peppermint candies.