Step 1

Preheat the oven to 350ºF and grease a 9X5 loaf pan with butter or oil.

Step 2

Add the softened butter to a large bowl with a hand mixer, OR a stand mixer fitted with the paddle attachment.

Step 3

Add in granulated sugar and brown sugar to the butter and mix on medium-high speed until the butter and sugars have creamed and are light and fluffy, about 2-3 minutes.

Step 4

Add the egg, vanilla and buttermilk and mix until fully incorporated.

Step 5

Sift the flour and baking soda into the bowl and mix just until it starts to come together. Use a silicone spatula to fold everything together until the flour is absorbed and no large lumps remain.

Step 6

Stir together ⅓ cup of sugar and 1 ½ teaspoons of cinnamon and set aside.

Step 7

Add half of the batter to the prepared loaf pan, and add half of the cinnamon sugar mixture evenly on top of the batter. Use a butter knife to swirl it into the batter.

Step 8

Add the remaining half of the batter on top, smoothing it out evenly.

Step 9

Add the remaining cinnamon sugar mixture and swirl it into the top layer of batter using a butter knife.

Step 10

Drizzle 2 tablespoons of melted butter on top of the loaf.

Step 11

Bake in the preheated oven for 50-70 minutes, or until a cake tester (or toothpick) comes out clean when inserted into the center.

Step 12

Allow to cool in the pan for 20 minutes, and then gently coax it out of the loaf pan and transfer to a wire rack. Allow to cool to room temperature before wrapping and storing.