Heat oven to 375°F. Spray large cookie sheet with nonstick cooking spray. Separate dough into 3 rectangles. Firmly press perforations to seal. Cut rectangles in half crosswise to make 6 pieces, each about 5 1/2x4 inches. Place dough pieces on sprayed cookie sheet. Press each to form 5 1/2-inch square.
Arrange chicken evenly on dough squares, folding under edges of chicken as necessary to fit dough. Spread chicken with 1 to 2 tablespoons barbecue sauce. Top each with cheese slice to fit.
With kitchen scissors, cut into each sandwich from each corner to within 1 inch of center. Fold alternating points to center of each, overlapping and pressing center to seal. Brush each with egg white. Sprinkle dough with sesame seed.
Bake at 375°F. for 13 to 18 minutes or until golden brown. Serve sandwiches with additional barbecue sauce.