Chocolate Waffle Cookies

Melt chocolate with 1 cup butter (2 sticks) in a saucepan over medium-high heat, stirring constantly. Let cool slightly.

Put eggs, vanilla, and granulated sugar in bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed until pale, 4 to 5 minutes. Mix in chocolate mixture, salt, cinnamon, 1/2 cup cocoa powder, and the flour.

Heat a waffle iron until hot. Lightly coat grids with cooking spray. Spoon about 1 tablespoon batter onto center of each waffle-iron square to make 1 1/2-inch rounds. Close cover; cook until set, about 1 1/2 minutes. Transfer to a wire rack, bottom sides up. Let cool completely. Repeat with remaining batter, coating grids with cooking spray after each batch.

Melt remaining 2 tablespoons butter in a small saucepan over low heat. Add confectioners' sugar and remaining 2 tablespoons cocoa powder; stir until smooth. Stir in milk.

Gently dip 1 surface of each cookie in icing so that just the waffle lines (not gaps) are coated. Repeat with remaining cookies and icing. Transfer to wire racks; let stand until set, about 10 minutes. Dust iced surfaces of cookies with confectioners' sugar.