Preheat oven to 350°. Coat muffin cups with cooking spray or use paper liners; set aside., In a bowl, combine the first 6 ingredients. Combine egg and oil; stir into dry ingredients just until moistened. Fold in the zucchini, walnuts and currants. , Fill muffin cups three-fourths full with batter. Bake until a toothpick in center comes out clean, 22-25 minutes. Cool for 5 minutes before removing from pan to a wire rack.