Preheat the oven to 400°. In a bowl, sift the flour with the baking soda, baking powder and salt. In another bowl, using a handheld electric mixer, beat the butter with 1 cup of the sugar until creamy. Add the melted chocolate and the egg and beat until smooth. Beat in the dry ingredients until incorporated.
In a shallow bowl, mix the remaining 1/2 cup of sugar with the cinnamon. Roll the dough into 1-inch balls and roll in the cinnamon sugar. Transfer to 3 parchment paper–lined baking sheets and flatten to 2-inch rounds. Bake for 12 to 14 minutes, until the cookies are puffed and cracked. Transfer to racks and let cool.