1) Preheat the oven to 375°F. Lightly grease two baking sheets, or line with parchment.
2) Combine the butter, sugars, baking soda, salt, espresso powder, and cinnamon in a mixing bowl.
3) Beat until the mixture is smooth.
4) Add the egg and vanilla, and again beat until thoroughly combined. The mixture will look a bit grainy; that's OK.
5) Beat in the cocoa.
6) Add the flour, beating slowly to combine.
7) Add the chips, mixing until they're well-distributed.
8) Drop the dough by teaspoonfuls onto the prepared baking sheets. A teaspoon scoop works very well here. If the dough begins to stick, simply dip the scoop in cold water. Space the cookies at least 1" apart.
9) Bake the cookies for 7 to 8 minutes; the cookies should seem barely done. If you attempt to pick an oven-hot cookie off the baking sheet, it'll fall apart.
10) Allow the cookies to cool right on the baking sheet.