Preheat oven to 350°F (175°C). Line a loaf pan with parchment paper.
In a bowl, whisk together flour, baking soda, salt, ginger, cinnamon, nutmeg, and cloves.
In another bowl, whisk the egg and vanilla until smooth.
In a stand mixer, cream the butter and brown sugar until fluffy. Add the molasses and mix until smooth, scraping the bowl as needed.
Pour in the egg mixture and beat for 1 minute.
Remove mixer paddle. Using a spatula, fold in ⅓ of the dry ingredients, then ⅓ of the buttermilk. Repeat until everything is incorporated. Do not overmix.
Transfer the batter to the prepared loaf pan.
Bake for 50–55 minutes, or until a toothpick inserted in the center comes out clean.
Cool for 20 minutes, then lift from the pan and cool completely on a rack.