Heat the oven to 350°F (175°C) with a rack in the center. Grease a 9x5-inch loaf pan and line it with a strip of parchment that hangs over the long sides.
In a medium bowl, whisk the flour, baking soda, salt, cinnamon, ginger, nutmeg and cloves until evenly mixed.
In a large bowl, whisk the melted butter with the brown and granulated sugar until no lumps of brown sugar remain. Whisk in the eggs one at a time, then the pumpkin, milk and vanilla.
Add the dry ingredients to the wet and fold with a spatula just until no dry flour is visible. Small lumps are fine.
Scrape the batter into the pan and smooth the top. Mix the topping sugar and cinnamon and sprinkle it over, if using.
Bake for 55 to 65 minutes, until a toothpick in the center comes out clean or with a few moist crumbs, or the center reads 200–205°F (93–96°C). If the top darkens too fast, cover loosely with foil after about 40 minutes.
Cool in the pan for 15 minutes, then lift out onto a wire rack. Let it cool for at least 1 hour before slicing.