Place buttermilk in one bowl and set aside.
In a separate bowl, mix flour, salt, pepper and baking powder.
Heat oil to 375° F for frying.
Dredge onion rings in flour mixture first, then dip in buttermilk. Coat with flour mixture again.
Place onion rings in hot oil without crowding onion rings. When onion rings are golden brown, remove from oil and drain.Makes 4 Source: