Preheat the oven to 350°F. Spray a 9x5 loaf pan with baking spray, or line it with parchment paper and spray with baking spray, set aside. In a medium-sized bowl, stir together the flour, baking soda, cinnamon, baking powder, and salt until combined, set aside.
In a large bowl cream together the butter, sugar, and brown sugar for 2 minutes until combined. Add the egg and mix it in. Add the buttermilk and vanilla, slowly stir it in until combined. Add the dry ingredients to the wet and mix it in until just combined, with no dry patches.
In a small bowl stir together the sugar and cinnamon. Add ½ of the batter to the pan and smooth it out. Add ⅔ of the cinnamon mixture on top evenly. Add the remaining batter, smooth out the top. Add the remaining cinnamon sugar, swirl the top with a butter knife.
Bake for 40-45 minutes until a toothpick inserted into the center comes out clean. Let cool in the pan for 10 minutes. Take the bread out of the pan and let it cool completely on a wire rack.
To Store: You can store your quick bread at room temperature for up to 3 days in an air tight container.
To Freeze: If freezing quick bread, wrap it very well in plastic wrap and place it in the freezer for up to 3 months.
Make sure your quick bread has completely cooled before slicing. If you try to slice it warm, the center will sink and it will likely fall apart!
Lining the loaf pan with parchment paper makes it easier to lift out of the pan and will keep the cinnamon sugar topping in tact.
This recipe can easily be doubled to make two loaves.