Heat oven to 375°F. Spray large cookie sheet with cooking spray.
Unroll both cans of dough. Place rectangles of dough side by side on cookie sheet with long sides together. Press into 15x12-inch rectangle, firmly pressing perforations and seams to seal.
Place corned beef evenly in 6-inch wide strip lengthwise down center of dough. Top with sauerkraut. Spoon dressing evenly over sauerkraut. Sprinkle with cheese.
With kitchen scissors or sharp knife, make cuts 1 1/2 inches apart on long sides of dough rectangle to within 1/2 inch of filling. Twisting each strip once, alternately cross strips over filling. Bring short ends over filling, and press to seal. In small bowl, beat egg and water. Brush dough with egg mixture. Sprinkle top with pine nuts.
Bake 25 to 30 minutes or until deep golden brown. Let stand 5 minutes before serving. Cut into crosswise slices.