Sprinkle lamb evenly with salt and pepper. Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add 1 lamb rack to pan; cook 2 minutes on each side or until browned. Remove lamb from pan. Repeat with remaining lamb rack. Brush Dijon mustard over lamb, and press breadcrumb mixture over lamb. Place the lamb on a rack coated with cooking spray; place rack in a roasting pan. Bake at 450° for 18 minutes or until a thermometer inserted in thickest part of lamb registers 130°. Let stand 10 minutes. Cut into chops.