Preheat your oven to 350°F (175°C). Prepare two bread pans by either spraying them with non-stick spray or lining them with tinfoil.

In the bowl of a stand mixer fitted with a paddle attachment, cream together the butter and 2 cups of sugar until the mixture becomes light and fluffy.

Add the eggs and vanilla extract to the creamed butter mixture, and continue to mix until everything is well incorporated, scraping down the sides of the bowl as necessary.

Gradually add the flour, buttermilk, and baking soda to the mixture, allowing the mixer to run slowly to avoid flour spillage.

Pour one-quarter of the batter into each of the prepared bread pans.

In a small bowl, combine the remaining 1/3 cup of sugar with the 2 teaspoons of cinnamon.

Sprinkle one-quarter of the cinnamon-sugar mixture over the batter in the pans.

Divide the remaining batter evenly between the two pans, then sprinkle the tops with the remaining cinnamon-sugar mixture.

Use a toothpick or knife to gently swirl the cinnamon-sugar topping into the batter.

Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted into the center of the bread comes out clean.

Allow the bread to cool in the pans on a cooling rack for about 20 minutes.

Remove the bread from the pans and let them cool completely before slicing and serving.