• Preheat oven to 350°F.
• Grease 2 loaf pans and set aside.

Cinnamon/Sugar Mixture:

• In a small bowl stir together ⅔ cup sugar with 2 teaspoons cinnamon. Set aside.

Make the batter:

• In the bowl of a stand mixer, cream together 2 sticks softened butter with 2 cups sugar on high speed until light and fluffy, about 3-4 minutes.
• Reduce speed to low and add each egg, one at a time until combined. Turn speed to high and whip mixture until it's light and fluffy.
• Reduce speed back down to low and add buttermilk. Mix until combined.
• Slowly add flour and baking soda, a little at at time, until combined with the buttermilk batter. Batter will be quite thick.
• Pour ¼ of the buttermilk batter into each greased loaf pan.
• Sprinkle ½ of the cinnamon/sugar mixture over the batter in each pan.
• Divide the remaining batter evenly between the two pans. Spread it out to cover the cinnamon/sugar mixture.
• Sprinkle the remaining cinnamon/sugar mixture over each loaf.
• Swirl the cinnamon/sugar mixture into the batter with a knife.
• Bake loaves for 45-50 minutes or until a toothpick inserted in the middle of each loaf comes out clean.
• Cool loaves in the pans for 20 minutes before turning them out onto a wire rack to cool completely.