Mexican Hot Chocolate Cookies

Preheat the oven to 325 degrees F.
In the bowl of a stand mixer fitted with the paddle attachment (or a hand-held mixer), beat butter and sugar at medium speed with an electric mixer until light and fluffy.
Add vanilla extract, eggs, and milk on low speed until well combined.
In a medium bowl sift together the flour, cocoa powder, cinnamon, chili powder, baking soda, coffee, and salt.
Add the dry ingredients to the batter and mix on low speed until well-combined and no visible flour remains. Fold in the Mexican chocolate and chocolate chips with a rubber spatula or wooden spoon.
Refrigerate dough to scoop or roll easier for 1 hour or overnight.
Scoop balls of dough (preferably using a small ice cream scoop with a spring handle, about 2 tablespoon size) or roll balls of dough onto a parchment-lined sheet pan, leaving at least 2 inches of space between each cookie. Bake the cookies, one pan at a time, for approximately 14 minutes, rotating the pan halfway through cooking time. The cookies should be puffy and still fairly soft when removed from the oven.
Immediately slide the cookies, still on the parchment paper, onto a wire cooling rack. Cool just a bit before serving, 5 to 10 minutes.