Antipasto Lasagna

INGREDIENTS

• 1 (27.5-ounce) jar fat-free mushroom-and-roasted garlic pasta sauce
• Cooking spray
• 6 no-boil lasagna noodles
• 1 (14-ounce) can artichoke hearts, drained and coarsely chopped
• 1 (7-ounce) bottle roasted red bell peppers, drained and chopped
• 1/2 cup chopped turkey pepperoni (such as Hormel), divided
• 1/3 cup chopped pitted kalamata olives
• 1 cup (4 ounces) preshredded part-skim mozzarella cheese, divided
• Oregano sprigs (optional)