01 - Preheat the oven to 350°F. Grease a 9-inch square baking pan and line with parchment paper.
02 - In a medium bowl, whisk together flour, ground ginger, cinnamon, cloves, nutmeg, salt, and baking soda.
03 - In a large bowl, cream the softened butter and brown sugar until light and fluffy using an electric mixer or hand whisk.
04 - Beat in the egg until fully incorporated, then add the molasses and mix until smooth.
05 - Add the dry ingredients to the wet mixture in two parts, alternating with the hot water. Gently mix until just combined.
06 - Pour the batter into the prepared pan and smooth the surface. Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean.
07 - Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before serving.
08 - Serve plain or dusted with powdered sugar. For added flavor, top with whipped cream or vanilla ice cream.