In a medium bowl, whisk together the dry ingredients. Set aside.
In the bowl of a stand mixer (or in a large bowl with an electric hand mixer), add the butter, coconut oil, brown sugar, and granulated sugar. Cream together until well-mixed, 2-3 minutes.
Add the eggs, vanilla extract, and peppermint extract. Beat to fully combine. With the mixer running on low, slowly add the dry ingredients in 3 additions, beating well after each addition.
Stir in the Andes mints and chocolate chips. Cover and refrigerate the dough for at least 1 hour and preferably overnight.
When you're ready to bake the cookies, preheat the oven to 350F. Line two large, rimmed baking sheets with parchment paper or silpat liners. Scoop the dough and shape into heaping tablespoon-sized balls (I use a #40 cookie scoop). If using the crushed peppermint candy, gently roll the tops into the additional crushed mints, pressing lightly into the plate or bowl of crushed mints so they stick to the top of the cookie dough ball
Place the dough balls a couple inches apart on the prepared baking sheets. Bake for 11-13 minutes, until the edges are set and the center is mostly set. Cool the cookies for 3-4 minutes on the pan, then transfer to a wire rack to cool completely. Enjoy!