Step 1

Preheat the oven to 350 degrees. Grease a 9x5 loaf pan and set aside.

Step 2

In a medium bowl whisk together the flour, baking powder, and salt.

Step 3

In a large bowl cream together the softened butter and sour cream with both sugars until light and fluffy. Gently beat in the egg, milk and vanilla extract until combined.

Step 4

Pour the liquid mixture into the flour mixture and use a rubber spatula to stir just until combined don't over mix.

Step 5

In a small bowl stir together the granulated sugar and cinnamon for the topping.

Step 6

Pour half of the batter into the greased loaf pan and sprinkle with half of the cinnamon sugar mixture.

Step 7

Pour on the remaining batter, then use a butter knife to swirl the batter around a few times. Top with the remaining cinnamon sugar.

Step 8

Bake in preheated oven for 40-50 minutes.

Step 9

Allow the bread to cool in the pan for 10-15 minutes. Remove and allow to cool completely before serving.