Preheat the oven to 350°F (175°C) and grease a 9×5-inch loaf pan.In a large bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, nutmeg, cloves, and ginger.In another bowl, whisk together the pumpkin purée, granulated sugar, brown sugar, vegetable oil, eggs, and vanilla until smooth.Pour the wet ingredients into the dry ingredients and stir until just combined.Fold in the nuts or chocolate chips if using.Transfer the batter to the prepared loaf pan and smooth the top.Bake for 55–60 minutes, or until a toothpick inserted into the center comes out clean.Let the bread cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.Slice and enjoy plain or with butter.