Make a well in the middle of the dry ingredients and add the egg, butter, buttermilk and vinegar.
Incorporate the wet ingredients with the dry until well blended.
Form into a ball and cover with plastic wrap and refrigerate at least 30 minutes. You can leave it overnight if preferred. Roll out dough into a log and cut into 6-12 pieces.
In a pan, heat vegetable oil to 375 degrees. Use a candy thermometer as temperature is important. While you are waiting for the oil to heat up, mix the sugar and cinnamon in a bowl and set aside. Cook 6 dough balls at a time for approximately 1 minute. Drain on paper towel then roll in cinnamon sugar.
