• Preheat the oven to 350°F (180°C). Grease a 9x5-inch loaf pan with nonstick oil spray and set it aside.
• Combine ½ cup granulated sugar and 1 tablespoon ground cinnamon together in a bowl to make cinnamon sugar, and set aside.
• Whisk flour, baking powder, baking soda, and salt together in a medium bowl.
• Add oil, sour cream, sugar, and vanilla to a large bowl and whisk well. Add milk and mix until everything is well combined.
• Add the flour mixture to the wet and mix until combined, but do not overmix.
• Spread half of the batter evenly into the prepared pan. Sprinkle almost all the cinnamon sugar evenly on top, reserving about 2-3 tablespoon for topping.
• Carefully spread the remaining batter evenly on top of the cinnamon sugar layer. Spreading the top layer will be tricky, as it wants to stick to the cinnamon sugar filling. But use the back of a spoon to spread it out evenly as best you can.
• Sprinkle the rest of the cinnamon sugar on the top. Then, using a knife, make a large swirl down the loaf pan to create a swirl.
• Bake for 45-50 minutes or until a toothpick inserted in the center comes out clean. If the top of the loaf cake is browning too quickly, remove it from the oven after 30-35 minutes and loosely cover it with aluminum foil. Then, return it to the oven and continue baking for the remaining time.
• Once baked, remove the loaf cake from the oven and transfer the pan onto a wire rack.
• Allow the Cinnamon Swirl Quick Bread to cool entirely before removing from the pan and slicing

Serving Suggestions

• Eggless Cinnamon Swirl Quick Bread stays at room temperature, tightly covered, for 2-3 days.
• It stays longer in the fridge for up to a week.