Preheat oven to 350 degrees Fahrenheit, and spray the bottom of a loaf pan with cooking spray.

In a large bowl, combine the flour, 1 cup of sugar, baking soda and salt.

In a separate small bowl, mix the buttermilk, egg and oil until well combined. Then slowly stir this into flour mixture until blended.

To make the swirl, mix the cinnamon and 1/2 cup sugar in small bowl.

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

Pour the remaining batter and sprinkle the top with remaining swirl mixture.

Take a knife or spatula and drag through the batter to make a swirl.

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

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

For the glaze, place powdered sugar in a bowl and slowly add the milk. Continue to stir until you get a syrup consistency, then drizzle over loaf.