Preheat oven to 450°F.
In a large skillet, cook Italian sausage with onion and mushrooms until sausage is browned and onions and mushrooms are soft. Break up sausage into crumbles with a wooden spoon as it cooks.
Stir in bell pepper and garlic and cook for 1-2 minutes to combine.
Add Italian seasoning and stir to combine.
Add pepperoni, olives and marinara sauce. Stir to combine.
Remove pan from heat and stir in shredded Italian cheese.
Divide filling evenly between ramekins.
Roll out pizza dough and cut into 6 squares.
Top each ramekin with a square of pizza dough allowing the dough to hang over the edges of the ramekin.
Brush dough with beaten egg.
Top each dish with 2 slices of Mozzarella cheese, overlapping the slices.
Bake for 15-20 minutes or until the crust is golden brown, cheese is melted, and filling is hot and bubbly.