Heat oven to 375 degrees F. Separate dough into 4 rectangles.
Place on ungreased cookie sheet. Press each to 7x5 inches, firmly pressing perforations to seal.
Spread 1 tablespoon marinara sauce on each rectangle to within 1/2 inch of edges.
Place 8 slices of pepperoni in center of each rectangle; top with 1/3 cup cheese and 8 more slices pepperoni. Bring ends up over filling, overlapping about 1 inch. Press edges with fork to seal.
Brush each sandwich with water, and sprinkle with Italian seasoning.
Bake 13 to 15 minutes or until golden brown. Immediately remove from cookie sheet.