01 -
Preheat your oven to 350°F and grease a 9×5-inch loaf pan.
02 -
Use a mixer to cream the butter and sugar until light and fluffy. Then add the egg and vanilla to the mixing bowl and mix well.
03 -
In a medium bowl, combine the flour, baking soda, and salt.
04 -
Add half of the dry ingredients to the mixing bowl and half the buttermilk. Mix until just combined. Then add the rest of the flour and buttermilk and mix until combined.
05 -
In a small bowl, combine the cinnamon and granulated sugar to create the cinnamon-sugar mixture.
06 -
Spoon about half of the batter into the prepared loaf pan, leveling it with a spatula. Sprinkle two-thirds of the cinnamon-sugar mixture over the batter. Use a butter knife to swirl the mixture through the batter.
07 -
Put the remaining batter on top and smooth it over the cinnamon layer with a spatula. Sprinkle the rest of the cinnamon mixture on top.
08 -
Bake in the preheated oven for 45-50 minutes until golden brown. A toothpick inserted into the center should come out clean. Allow the loaf to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.