Sweet-and-Hot Onion Rings

2-1/2 cups all-purpose flour
1/2 cup cornstarch
1/4 cup sugar
3 tablespoons baking powder
1 tablespoon ground red pepper
2 teaspoons salt
2 cups club soda
Vegetable oil for frying
2 large sweet yellow onions, cut into 3/8-
   inch-thick slices and separated into rings

1. In a large bowl, combine the flour, cornstarch, sugar, baking powder, ground red pepper, and salt; whisk in the club soda.
    
2. In a large saucepan, heat 2 inches of oil over medium heat until hot but not smoking. Dip each onion ring into the batter, allowing the excess to drip back into the bowl. Fry a few rings at a time for 5 to 6 minutes, or until golden. Drain on a paper towel-lined platter before serving.