Step 1:
Spray large skillet with nonstick vegetable spray. Heat olive oil in
large skillet over medium heat.
Add onion and garlic; cook 5
minutes; stirring occasionally. Add tomato puree, tomatoes, tomato
liquid,
mushrooms, zucchini, bell pepper, basil, red pepper
flakes, oregano and salt and sugar, if desired. Heat
to a boil;
reduce heat, cover and simmer 10 minutes.
Step 2:
Combine Ricotta cheese, spinach, egg whites and Parmesan cheese in
bowl; set aside. Spread
1 cup tomato sauce mixture in bottom of
13x9-inch baking dish. Layer 3 lasagna noodles over sauce.
Top with half the Ricotta cheese mixture and 2 cups sauce. Repeat
layering with 3 more lasagna noodles,
remaining Ricotta mixture and 2 cups sauce. Sprinkle with 3/4 cup
Pizza Double Cheese. Top with remaining
lasagna noodles and
sauce.
Step 3:
Cover with foil; bake in preheated 375°F oven 30 minutes. Uncover;
bake 15 minutes more. Sprinkle with
remaining 3/4 cup Pizza
Double Cheese. Let stand 10 minutes before serving.