Preheat the oven to 350°F (175°C). Grease a 9×5-inch loaf pan and line it with parchment paper.
Brown the butter: In a saucepan over medium heat, melt butter. Continue cooking, stirring often, until it turns golden brown and smells nutty. Remove from heat and let cool slightly.
Mix wet ingredients: In a large bowl, whisk together the pumpkin puree, brown sugar, granulated sugar, eggs, vanilla, and cooled brown butter until smooth.
Combine dry ingredients: In a separate bowl, whisk flour, baking soda, baking powder, salt, cinnamon, nutmeg, ginger, and cloves.
Combine mixtures: Add dry ingredients to wet ingredients and stir until just combined. Avoid overmixing.
Add mix-ins: Fold in nuts or chocolate chips if using.
Bake: Pour batter into the prepared pan and smooth the top. Bake for 50–60 minutes or until a toothpick inserted into the center comes out clean.
Cool and serve: Allow the bread to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.