Sift together the flour, cocoa powder, baking soda, baking powder, and salt. Set aside.
With a mixer, cream together the softened butter, granulated sugar, and granulated sugar until creamy.
Add vanilla, peppermint extract, and eggs and mix again to combine.
Gently mix in the dry ingredients until fully incorporated, the dough will be sticky.
Fold in the chocolate chips and crushed peppermint. Line a baking sheet with parchment paper.
Using a cookie scoop or spoon, scoop 2 Tbsp of dough at a time, dividing into 24 scoops of dough. Add to the lined baking sheet and chill for 30 minutes.
Preheat the oven to 350°F and line another large baking sheet with parchment paper.
Roll the scoops of dough into evenly shaped balls and place onto the baking sheet, 1-2 inches apart from each other.
Bake at 350°F for 11-12 minutes or until the edges become golden.
Remove from the oven and top the cookies with additional crushed peppermint and flakey salt. (Optional- Drizzle with melted white chocolate before topping with additional crushed peppermint. )
Let the cookies chill for 5-10 minutes.
Serve warm or chilled.