Preheat the oven to 350 degrees Fahrenheit (175 degrees Celsius). Line the baking sheets with a baking mat or parchment paper. Set aside.

In a microwave-safe bowl, melt one stick of butter (about 45 seconds on HIGH).

In the bowl of a stand mixer or a large mixing bowl, combine the melted/room temperature butter, sugar, and vanilla. Beat until light and fluffy (about 2 minutes). Add the eggs one at a time and mix just until incorporated.

In a medium-sized mixing bowl, whisk together the flour, cocoa powder, baking soda, and salt. With the mixing speed on low, gradually add the dry ingredients along with the dissolved espresso mixture. Mix just until combined. Using a spatula, fold in the chocolate chips, crushed candy cane chunks, and chopped peppermint thins.

Using a standard-size cookie scoop (1.5 tablespoons), place the dough onto the prepared baking sheets (12 per sheet). Place the cookie dough balls into the oven and bake for 8–10 minutes. They will look slightly underbaked, but they will firm up and flatten as they cool. Allow them to cool on the sheets for 3 minutes before transferring to a wire cooling rack to cool completely.