Preheat a large shallow pot full of about 2 inches of oil over medium heat. You want it to be about 375 Fahrenheit.
In a medium sized bowl mix together theflour, baking powder, salt, cinnamon and sugar.
In a small bowl stir together the buttermilk and egg.
Dump your buttermilk and egg into the flour mixture and stir together.
In a small bowl, combine the cinnamon and sugar for the topping then dump onto a plate. Set it aside.
Slice your apples into thin round slices, about 1/4 inch thick.
Cut out and discard the core of the apples.
Cut each apple slice into 2 rings, one smaller from the middle and one bigger from the edge. (A round cookie cutter or biscuit cutter works great.)
Dip your apple slices into your batter and allow excess batter to drip off.
Put a few slices at a time into the preheated oil.
Allow to cook for about 2 minutes total, flipping over half way through when the bottom is a golden brown color. Cook until both sides are nicely golden brown.
Remove from oil and place on some paper towels to drip excess oil off.
Dip apple slices into cinnamon sugar mixture, and coat on both sides.
Serve hot.