Preheat oven to 400°F or 200°C.
Chop hazelnuts and two slices of whole-wheat bread with parsley flakes in food processor or blender until finely ground. In a small bowl combine Dijon mustard and honey. Rub lamb racks with pepper and salt, then sear on all sides in oil in skillet on medium-high heat. (About 5 minutes in total)
Transfer to board and allow to cool slightly. Coat fat-side of lamb with honey-mustard mixture and then press nut mixture into honey mixture to form a crust.
Place lamb, crusted side up on a wire rack in a roasting dish with the extended bones interlaced. Spritz crumb-coating mixture with a little olive oil and cook for 20 - 25 minutes until crust is golden and meat is cooked to desired level.