In a large bowl, cream the butter and sugar until light and fluffy. Beat in the egg, egg yolk and vanilla. Combine the flour, cocoa, baking powder, cinnamon and salt; add to the creamed mixture and mix well.
Divide dough in half. On a lightly floured surface, roll each portion to 1/8-in. thickness. Cut with a floured 2-in. cookie cutter. Place 1 in. apart on greased baking sheets. Bake at 350° for 7-8 minutes or until set. Let cool for 5 minutes before removing to wire racks to cool completely. Decorate with frosting if desired.
Every editorial product is independently selected, though we may be compensated or receive an affiliate commission if you buy something through our links.