Preheat oven to 425 degrees. Spray cake pan with cooking spray.
Lightly flour a board to prevent sticking. Roll out dough into a rectangle approximately 1/4-inch thick and 12x18 inches.
Add sauce leaving about 1/2-inch of border with bare dough. Top with cheese and spinach.
Roll up from short end into a log. Cut into 4 pieces. Place pieces cut side up into pan.
Whisk egg and a tablespoon of water together to form an egg wash. Brush exposed dough lightly with egg wash. Bake uncovered for about 25 minutes until dough is thoroughly baked and browned. Cool slightly before removing.