Oaxacan Mexican Chocolate Cookies

In a large bowl, beat the butter, sugars, mescal and salt with an electric mixer on medium to high speed for 30 seconds.

Sift the flour, cocoa powder, baking soda, and cinnamon into the butter mixture. Mix on low speed until dough just comes together and is no longer dry. Add chocolate and continue mixing until just combined.

Divide dough into four portions. Roll each portion into a 10-inch log. Wrap in waxed paper and chill for at least 1 hour.

Preheat oven to 325°. Using a very sharp knife dipped in hot water, cut dough into 1-inch-thick slices; place 1 inch apart, cut-side down, on ungreased cookie sheets.

Bake for 12 minutes, then very lightly brush cookies with egg. Sprinkle with sea salt and bake for 5 more minutes. Cool on cookie sheet for 5 minutes. Transfer to a wire rack and let cool.