I cannot remember where I picked up this recipe, but I tried it first in 1998, and have used it faithfully ever since. Makes a lovely loaf.
Combine ½ cup of the white sugar with the cinnamon. Set aside.
Combine egg, buttermilk and vegetable oil together in a small bowl. In a large bowl, combine flour, remaining one cup white sugar, baking soda and salt. Make a well in the center of the flour mixture and pour in the egg mixture; mix well.
Spread half of the batter into a greased loaf pan. Sprinkle half of the cinnamon and sugar mixture over the batter.
Spread remaining batter and sprinkle the rest of the cinnamon evenly. Bake at 350 degrees about 30 to 45 minutes, testing for doneness with toothpick.