For sauce, drain plums. Reserve liquid. Pit plums. In food processor or blender, combine plums, plum liquid reserve, hoisin sauce, orange juice concentrate, soy sauce, ginger and black pepper. Cover and process / blend until nearly smooth.
Transfer mixture to saucepan. Bring to boil, then reduce heat. Simmer uncovered for 15 minutes or until slightly thickened. Stir occasionally.
Arrange drummettes on rack of unheated broiler pan. Broil 5 to 6 inches from heat for 8 minutes. Brush with some sauce, then turn and brush again. Broil 6 to 8 minutes more or until tender and no longer pink.
In small saucepan, bring remaining sauce to boiling. Transfer to small bowl. Arrange drummettes on serving plate. Sprinkle with sesame seeds. Serve sauce with drummettes.
For extra fire in the sauce, add cayenne pepper to the plum mixture before cooking.