Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan with cooking spray or line it with parchment paper for easy removal.
In a large mixing bowl, combine the canned pumpkin puree, vegetable oil, brown sugar, and granulated sugar. Whisk until smooth.
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
In another bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, and nutmeg.
Gradually add the dry ingredients to the wet ingredients, stirring gently until just combined. Be careful not to overmix.
Fold in the chocolate chunks and the optional chopped walnuts for added crunch and flavor.
Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
Bake in the preheated oven for 55 to 65 minutes, or until a toothpick inserted into the center comes out clean.
Once baked, remove the bread from the oven and let it cool in the pan for about 10 minutes. Then, transfer it to a wire rack to cool completely before slicing.
Notes
Serve slices with a dusting of powdered sugar on top and a drizzle of chocolate sauce or a dollop of whipped cream for an extra indulgent touch!