Preheat the oven to 375°F (190°C).
Roll out the pizza dough on a floured surface.
Fit one piece of dough into a greased pie dish.
In a mixing bowl, combine marinara, mozzarella, sausage, bell peppers, mushrooms, olives, and Italian seasoning.
Spoon the filling mixture into the dough-lined dish.
Roll out the second piece of dough and lay it over the filling.
Brush the top with beaten egg.
Bake in the preheated oven for 30-35 minutes, or until golden brown.
Remove from the oven and let it cool for 10 minutes before slicing.