1. Preheat oven to 375°F. Heat large nonstick skillet over medium heat until hot. Add Ground Beef; cook 8 to 10 minutes, breaking into small crumbles and stirring occasionally. Remove skillet from heat; stir in pasta sauce and red pepper.
2. Meanwhile, combine ricotta cheese, 1/2 cup mozzarella cheese, Parmesan cheese and egg whites in medium bowl.
3. Spread one third of beef mixture in bottom of 13 x 9-inch baking dish. Top with half of zucchini slices in single layer. Spread half of ricotta mixture over zucchini. Repeat layers with another third of beef mixture, remaining zucchini slices and remaining ricotta mixture. Top with remaining beef mixture. Sprinkle with remaining 1/2 cup mozzarella cheese.
4. Bake, uncovered, in 375°F oven 45 to 50 minutes or until zucchini is tender and cheese is golden brown. Let stand 10 to 15 minutes before serving.
Test Kitchen Tips Cooking times are for fresh or thoroughly thawed Ground Beef. Ground beef should be cooked to an internal temperature of 160°F. Color is not a reliable indicator of ground beef doneness.