Beat butter at medium speed with an electric mixer until creamy; gradually add sugar and salt, beating well. Add molasses, vinegar, and egg, beating at low speed just until blended.
Combine flour and next 4 ingredients; add to butter mixture, beating at low speed until blended. Cover and chill 8 hours.
Divide dough into fourths. Roll each portion to a 1/8-inch thickness on a floured surface. Cut with a 3-inch gingerbread-boy cookie cutter. Place on lightly greased or parchment paper-lined baking sheets.
Bake at 375° for 8 minutes. Cool on pans 1 minute (this allows cookies to lift easily off of pan); then place on wire racks to cool. Decorate as desired.