Heat oven to 400°F. Spray 8 or 9-inch square pan with nonstick cooking spray.
In large bowl, combine sugar and sweet potatoes until well mixed. Add milk, oil and egg; mix well.
Lightly spoon flour into measuring cup; level off. Add flour, baking powder, nutmeg and allspice to sweet potato mixture; stir until well combined. Stir in currants. Pour batter into sprayed pan.
Bake at 400°F. for 12 to 19 minutes or until bread is light golden brown and center is firm to the touch. Cut into squares. Serve warm or cool.