Preheat your oven to 350°F (175°C).
In a mixing bowl, combine the pumpkin puree, sugar, and vegetable oil.
Add the eggs one at a time, mixing well after each addition.
In another bowl, whisk together the gluten-free flour, baking powder, cinnamon, and nutmeg.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Pour the batter into a greased baking pan.
Bake for 30 minutes or until a toothpick inserted into the center comes out clean.
Let it cool before serving.