Preheat oven to 350 F (175 C). Line two baking sheets with parchment.

In a large bowl, whisk together the dry ingredients: flour, cocoa, sugar, baking powder, salt, cinnamon, cloves, and nutmeg. Stir in the orange zest.

In a second bowl, whisk together the wet ingredients: melted butter, eggs, milk, coffee, and vanilla until smooth.

Pour the wet mixture into the dry ingredients. Stir until a soft dough forms. If the dough looks dry, add milk a tablespoon at a time.

Fold in any optional nuts, chips, or raisins if using. Chill the dough for 10 to 15 minutes.

Scoop small mounds of dough, about a heaping tablespoon each, and roll into balls. Arrange them 2 inches apart on baking sheets.

Gently flatten the tops with damp fingers.

Bake for 12 to 14 minutes until set on the edges and just firm on top.

Cool on the pan for 5 minutes, then transfer to a rack to cool completely before glazing.

Whisk together the glaze ingredients until smooth and pourable.

Dip the rounded tops of the cooled cookies into the glaze and set them back on the rack. Let the glaze set for 30 minutes.