Prepare cookie mix as directed on package, adding vanilla. Cut out rounds with 2 1/2-inch round cookie cutter.
Bake and cool cookies as directed on package.
Frost cookies with vanilla frosting. For the scarecrow’s hat, break a sugar wafer cookie in half. Press wafer cookie half into the top of the frosted cookie. Place a whole wafer cookie below the cookie half. Press shredded wheat around sides of the face for straw hair. Use candy-coated pieces and string licorice to decorate the face.