Combine the flour, 1 cup sugar, baking soda and salt in a large bowl.

MIx together buttermilk, egg and oil and stir into flour mixture until blended.

Mix together cinnamon and 1/2 cup sugar in small bowl.

Spray the bottom of a loaf pan with cooking spray.

Pour half of the batter into pan then sprinkle 2/3 of the swirl mixture.

Pour remaining batter and sprinkle with remaining swirl mixture.

Take a knife or spatula and cut through batter to swirl.

Bake at 350 for 60-70 minutes or until a toothpick inserted comes out clean (cooking times vary a lot).

Cool for 10 minutes in pan then remove and place on wire rack.

Place powdered sugar in a bowl slowly add milk stiring until you get to syrup consistency, then drizzle over loaf.