Place butter in a large bowl; beat with a mixer at medium speed until fluffy. Gradually add 2/3 cup sugar, beating at medium speed until light and well blended. Add molasses and egg; beat well.
Lightly spoon flour into dry measuring cups, and level with a knife. Combine flour and the next 4 ingredients (through mace), stirring with a whisk. Gradually add flour mixture to butter mixture, stirring until well blended. Divide dough in half. Wrap each portion in plastic wrap, and freeze for 30 minutes.
Preheat oven to 350°.
Shape each portion of dough into 26 (1-inch) balls. Roll balls in remaining 3 tablespoons sugar, and place 2 inches apart on baking sheets coated with cooking spray. Flatten cookies with the bottom of a glass to 1/2-inch thickness. Bake at 350° for 12 minutes or until lightly browned. Remove from pans, and cool completely on wire racks.