Heat the oven and prep the pan. Heat the oven to 350°F. Grease a 9x5-inch loaf pan and line it with parchment, leaving overhang on the long sides.
Whisk the dry ingredients. In a medium bowl, whisk together the flour, baking soda, baking powder, ginger, cinnamon, cloves, nutmeg, and salt.
Cream the butter and sugar. In a large bowl, beat the butter and brown sugar until light and fluffy, about 2 minutes. Beat in the molasses, then the egg.
Alternate the dry mix and the buttermilk. Add the dry ingredients in three parts, alternating with the buttermilk and starting and ending with the dry mix. Stir just until combined — a few streaks of flour are fine.
Stir in the hot water. Pour in the hot water and stir until smooth. The batter will look thin; that is right.
Bake. Pour the batter into the pan and bake 50 to 60 minutes, until a toothpick inserted in the center comes out clean. Cool 10 minutes in the pan, then lift the loaf out by the parchment and cool completely on a rack before slicing.