Chicago-Style Pan Pizza

1 (1-lb) package of pizza dough or frozen bread dough, thawed
1 lb. bulk Italian sausage
2 cups shredded mozzarella cheese
2 tsp. olive oil
8 oz. sliced fresh mushrooms
1 small onion, chopped
1 (28-oz.) can diced tomatoes, well drained
3/4 tsp. dried oregano
1/2 tsp. salt
1/4 tsp. fennel seed
1/4 tsp. garlic powder
1/2 cup freshly grated Parmesan cheese

Preheat oven to 350.  Press dough into the bottom and up the sides of a greased 9x13-inch baking pan (gently stretch the dough as you press it).  Bake for 15 minutes.  Meanwhile, crumble and brown sausage in a large skillet.  Remove with a slotted spoon and set aside. Drain grease from pan and add olive oil; add mushrooms and onion and cook until onion is tender.  Stir in tomatoes, oregano, salt, fennel seed and garlic powder.  Simmer 5-10 minutes or until liquid is reduced and sauce is slightly thickened.  Layer over crust:  cooked sausage, half of mozzarella (one cup), sauce, remaining mozzarella (1 cup, or more if you want), and Parmesan.  Bake another 20-25 minutes or until crust is golden and cheeses are melted and bubbly.