Preheat the oven to 350°F (175°C) and grease a 9×9-inch baking pan or line with parchment paper.
In a large bowl, combine the pumpkin puree, sugar, and oil. Whisk until smooth. Add the eggs one at a time, mixing well after each addition.
In another bowl, whisk together the flour, baking powder, cinnamon, and salt.
Slowly add the dry ingredients to the wet mixture, stirring until just combined. Avoid overmixing.
Pour the batter into the prepared baking pan, spreading it evenly.
Bake in the preheated oven for 30-35 minutes or until a toothpick comes out clean.
Allow to cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.
Slice and serve warm or at room temperature, optionally dusted with powdered sugar.