1In large bowl, mix granulated sugar, brown sugar, peanut butter, butter, shortening and egg until well blended. Stir in flour, baking soda, baking powder and salt until blended. Cover; refrigerate at least 3 hours.
2Heat oven to 375°F. Divide dough in half. On lightly floured surface, roll each half of dough 1/8 inch thick. Cut with 3x2-inch ghost-shaped cookie cutter. On ungreased cookie sheet, place shapes about 2 inches apart. If cookies are to be hung as decorations, cut a hole at top of each cookie with end of plastic straw or sharp knife; cut out holes for eyes if desired.
3Bake 6 to 8 minutes or until light brown. Cool 2 minutes; remove from cookie sheet to cooling rack. Cool completely, about 30 minutes.
4In medium bowl, mix glaze ingredients until smooth and spreading consistency. Spread glaze on cookies. Decorate with candies. Thread string through holes to hang cookies.