Preheat your oven to 350°F (175°C) and grease an 8x8 inch baking dish.
In a mixing bowl, combine the melted butter, brown sugar, and maple syrup until smooth.
Add the pumpkin puree, eggs, and vanilla extract to the bowl, mixing well.
In another bowl, whisk together the flour, baking powder, cinnamon, nutmeg, and salt.
Gradually add the dry mixture to the wet mixture, stirring until just combined.
Pour the batter into the prepared baking dish and spread it evenly.
Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.
Allow the blondies to cool in the pan for 10 minutes before transferring them to a wire rack.
Once cooled, cut into squares and serve, optionally drizzling with additional maple syrup.