Preheat oven to 350°F.
Brown Italian sausage in a skillet over medium heat and drain excess grease.
Cook gnocchi according to package directions, remove from heat and drain.
Combine sausage, gnocchi, pasta sauce, Italian seasoning and 1 cup of mozzarella cheese.
Spray a 9x13-inch baking dish with nonstick cooking spray and pour in gnocchi mixture. Spread evenly in pan.
Bake for 25 minutes or until heated through.
Top with remaining mozzarella cheese and bake for another 10 minutes or until cheese is melted.