Peanut Butter and Jam Sandwich Surprises

1. Combine flour, sugar, baking soda and salt in large bowl; cut in peanut butter and shortening, using pastry blender or 2 knives until mixture resembles coarse meal.
2. Combine milk, egg yolk and vanilla in small bowl, beat with fork until blended. Add to flour mixture. Transfer mixture to an electric mixer; beat at low speed until well blended. Divide dough in half. Wrap with plastic wrap. Refrigerate at least 1 hour.
3. Preheat oven to 350ºF (180ºC).
4. Roll each half of dough between sheets of waxed paper or plastic wrap to 1/8 inch (3mm) thickness. Using a 2” (5cm) round cookie cutter, cut into 24 rounds. Place half the cutouts 1” (2.5cm) apart on ungreased baking sheets. Place about 1 tsp (5mL) jam in the center of each. Top with remaining cutouts. Press edges with a fork. Pierce several times with toothpick. Sprinkle tops of cookies lightly with sugar.
5. Bake in preheated oven 10-12 minutes or until golden brown. Sprinkle again with sugar. Cool 2 minutes on baking sheets. Transfer to cooling racks to cool completely.