01 - Preheat oven to 350°F. Grease and flour an 8-inch square baking pan.
02 - Whisk together flour, ground ginger, cinnamon, cloves, nutmeg, baking soda, and salt in a medium bowl.
03 - Using a mixer, beat unsalted butter with brown sugar until light and fluffy.
04 - Beat in the egg followed by molasses, mixing thoroughly after each addition.
05 - Gradually add dry ingredients to the wet mixture, stirring until just combined.
06 - Stir in hot water until batter is smooth and slightly thin.
07 - Pour batter into prepared pan and smooth the surface evenly.
08 - Bake for 35 minutes or until a toothpick inserted into the center comes out clean.
09 - Allow to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
10 - Serve plain, dusted with powdered sugar, or accompanied by whipped cream.