Sift together cornmeal, baking powder, soda, sugar, and salt; stir in buttermilk and egg, mixing well. Heat well greased cast iron corn stick pans in a 400ºF.  oven for 3 minutes or until very hot. Spoon batter into pans, filling two thirds full. Bake at 400ºF.  for 25 minutes or until lightly browned.