In a medium bowl, mix together the flour, cocoa, baking soda, baking powder, salt, and cinnamon.

In a large bowl, mix together melted butter, brown sugar, 3/4 cup granulated sugar, and vanilla.

Add the egg and egg yolk, and whisk together until mixture is smooth.

Switch to a spatula or wooden spoon and slowly mix the flour mix into the wet mixture in three parts. Before adding the last part of flour, add the coffee.

Roll into tablespoon sized balls, and roll into extra sugar. Place on a lined baking sheet.

Press cookies down lightly with the bottom of a glass. Bake at 350 for 10-12 minutes, until puffy and cracked.