Combine sugar, black pepper, cayenne pepper, ginger and salt in small bowl.
Heat heavy medium skillet over medium-high heat until hot. Add walnuts in single layer; cook 3 minutes or until fragrant and lightly browned, stirring frequently.
Stir in sugar mixture; cook 1 minute or until walnuts are well-coated with sugar, stirring constantly. (Do not let sugar dissolve completely; leave some grainy texture on the walnuts.).