On lightly floured board, roll puff pastry into 11-inch rectangle. Cut into two 6-inch rectangles and three 1-inch strips. Place 1 rectangle on ungreased cookie sheet.
Moisten edges of puff pastry with water. Place one 1-inch strip on each long side to form rim. Cut remaining strip in half; overlap on each short side to complete rim. In small bowl, combine jam and Nestle Toll House semi-sweet chocolate morsels.
Spoon filling down center of pastry, leaving rim clear of filling. Fold second rectangle in half lengthwise. With sharp knife, leaving 1-1/2 inch border, cut 1-inch-long lines, 1/2 inch apart, down length of pastry. Moisten edges of folded pastry and filled pastry.
Set folded pastry on top of filled pastry. Unfold top pastry and press edges together. Score border with crisscross design. Chill 15 minutes. Preheat oven to 425° F. In cup, combine egg and water; beat with fork. Brush over pastry.
Bake at 425° F for 20 minutes. Reduce oven temperature to 350° F and bake for 15-20 minutes. Cuol completely on wire rack.Servings: