Heat oven to 350°F. Spray cookie sheets with cooking spray. In medium bowl, stir cookie dough, egg yolk and flour until well mixed.
Take you cookie mixture and roll into golfball size balls. Next take you orange sprinkles and pour into a small bowl. Roll your cookie balls around in the sprinkles to coat with an orange color. Next take a tooth pick and indent the sides of the cookie balls to make the pumpkin shape. Place on your cookie sheet and then insert pretzel halves into the top. Bake for 12 minutes; take out to make sure the pretzels are still in place, then cook for an additional 2 minutes.