Peanut Butter Pumpkin Cookies

1
Heat oven to 350. Spray cookie sheets with cooking spray. Using electric mixer on medium speed, blend cookie dough, egg yolk and flour until well mixed.
2
Pour sugar crystals into small bowl. Shape dough into 28 (1 inch) balls; roll in sugar crystals. Insert 1 pretzel piece into each ball for pumpkin stem. Using the tip of a teaspoon or cheese spreader, make lines around sides for pumpkin ridges. Place balls 2 inches apart on cookie sheets.
3
Bake 9-11 minutes or just until set in center when touched with fingertip. Cool 2 minutes; remove from cookie sheets to cooling racks. Cool completely, about 10 minutes. Decorate with green frosting if desired.