Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking dish.
In a large bowl, whisk together the flour, sugar, baking soda, baking powder, pumpkin pie spice, and salt until combined.
Make a well in the center of the dry ingredients; add the pumpkin puree, eggs, and oil. Stir until just combined.
Pour the batter into your prepared baking dish and spread it evenly.
Bake for about 25-30 minutes, or until a toothpick comes out clean.
Let the cake cool in the pan for 10 minutes before transferring to a wire rack.
Slice and serve. Optionally dust with powdered sugar or frosting.