Preheat the oven to 350°F (176°C).
In a large bowl: combine pumpkin puree, oil, sugar, vanilla extract and 1 egg; mix. Then add the other egg to the bowl and mix.
Place a strainer over the top of the bowl (a sifter will also work as a substitute).
Add flour, baking soda, baking powder, salt and cinnamon to the strainer/sifter and mix together. Then sift all dry ingredients onto the wet mixture (finer powder helps prevent lumps).
Mix the contents of the bowl until a smooth batter is formed.
Coat the loaf pan with a No-Stick Cooking Spray (PAM made with Flour works well).
Pour the batter in the well coated loaf pan and place in the oven.
Bake for 55 minutes or until a toothpick placed in the center of the bread comes out clean.
Remove from the oven and rest the bread in the pan for 10 minutes.
Remove the bread from the loaf pan and transfer to a cake rack.