Preheat oven to 375 degrees F. Line a large baking sheet with Reynolds Wrap® Non-Stick Aluminum Foil; sprinkle with cornmeal. Set aside.
Brown sausage in large skillet on medium-high heat. Drain and set aside.
Unroll pizza dough onto prepared baking sheet. Carefully stretch or roll dough into a 13x10-inch rectangle. Arrange sausage on dough to within 1/2 inch of the edges. Sprinkle with 1/2 cup of the mozzarella. Layer spinach on cheese. Top with the remaining 1/2 cup mozzarella and the Parmesan. Starting from a long side, roll up dough to make a 13-inch-long loaf. Pinch seam and ends to seal.
Place loaf, seam side down, on the prepared baking sheet. Brush with egg. Using a sharp knife, cut four 2-inch slits in top for steam to escape.
Bake 20 to 25 minutes or until golden brown. If necessary, cover the last 5 minutes of baking to prevent overbrowning. Remove from oven and slice into rounds to serve with pizza sauce.