Step 1: Prepare Your Oven and Baking Pans
Preheat your oven to 350°F (175°C) and adjust the oven rack to the middle position. If using mini loaf pans, lightly grease them and line with parchment paper, ensuring the paper is long enough to hang over the sides to help lift the bread out of the pans. If using a brownie pan, line 5 of the wells with 1-inch strips of parchment paper that hang over the sides.

Step 2: Mix the Wet Ingredients
In a medium mixing bowl, add the egg, granulated sugar, light brown sugar, canned pumpkin, oil, and vanilla extract. Whisk these ingredients together until you achieve a smooth and well-combined mixture.

Step 3: Combine the Dry Ingredients
Using a fine mesh strainer or sifter, sprinkle the flour, baking powder, baking soda, pumpkin pie spice, and salt over the wet mixture. Gently whisk until no dry streaks remain, ensuring that the batter is smooth and free of lumps.

Step 4: Fill the Baking Pans
Scoop the batter evenly into the prepared baking pans. Spoon a generous amount of cinnamon sugar over the top of the batter, then gently swirl it using a toothpick or knife. This will create a beautiful, marbled effect on the surface of your bread.

Step 5: Bake the Pumpkin Bread
Place the pans in the preheated oven. If using a brownie pan, bake for 20 to 23 minutes; for mini loaf pans, bake for 28 to 30 minutes, or until a toothpick inserted into the center comes out mostly clean.

Step 6: Cool the Bread
Allow the pumpkin bread to cool in the pans for 10 to 15 minutes on a wire cooling rack. Once slightly cooled, use the parchment paper sling to lift the bread out of the pans and let it cool completely on the wire rack.