Heat the oven to 350°F (175°C). Grease a 9 x 5-inch loaf pan and line the bottom with parchment paper, leaving a little overhang to make the finished loaf easier to lift out.

Whisk the flour, baking soda, salt, ground ginger, cinnamon, cloves, and optional nutmeg together in a medium bowl. Breaking up any spice or flour lumps now helps the seasonings distribute evenly through the batter.

In a separate large bowl, whisk the melted, slightly cooled butter and brown sugar until combined. Add the molasses, egg, and vanilla, then whisk until the mixture looks smooth and glossy.

Add the dry ingredients in two or three additions, alternating with the buttermilk or whole milk. Stir gently after each addition and stop as soon as no visible streaks of flour remain.

Pour the batter into the prepared loaf pan and smooth the top with a spatula. Bake for 45–55 minutes, until a toothpick inserted in the center comes out with a few moist crumbs but no wet batter.

If the top begins to brown too quickly, loosely cover the loaf with foil during the final 10–15 minutes of baking. This protects the fragrant crust while the center finishes cooking.

Let the loaf cool in the pan for about 20 minutes, then carefully transfer it to a wire rack. Cool completely before slicing so the crumb can set and the molasses flavor can develop.