Preheat oven to 350°F (175°C).
In a mixing bowl, combine pumpkin puree, sugar, and vegetable oil. Mix well.
Add eggs one at a time, beating well after each addition.
In another bowl, whisk together flour, baking powder, baking soda, cinnamon, and salt.
Gradually add dry ingredients to the pumpkin mixture, mixing until just combined.
Pour batter into a greased baking pan and spread evenly.
Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Allow to cool before cutting into bars.