Rinse Cornish hens; pat dry with paper towels. Pull neck skin to back, fasten with a short skewer. Tie legs to tail and wings close to body. In a small bowl, combine sugar, garlic powder, cumin, paprika, coriander, salt, cinnamon, pepper, and nutmeg. Brush hens with oil. Sprinkle with the spice mixture; rub in with your fingers.