Mix 2 T of the cajun seasoning (Paul Prudhomme's Poultry Magic is very good) into the turkey along with the amount of cayenne pepper you would like. Now form the turkey into patties. Sprinkle the remaining 1 T cajun seasoning on the burgers (both sides). Either grill outside or pan-fry in a skillet with a bit of canola (or other vegetable) oil. (If you pan-fry, you will probably have to cover the burgers at the end and let them "steam" for about 5 minutes to finish cooking them.