Preheat the oven to 350°F. In a medium bowl, whisk flour, baking soda, ginger, cinnamon, salt, allspice, and nutmeg.
Place 4-6 ramekins on a baking sheet and coat each ramekin with non-stick spray.
In a small bowl, mix together the 1⁄2 cup of water and molasses, then set aside.
In a medium bowl with a whisk or electric mixer, mix together the butter and sugar until creamy. Add in the egg and continue beating until well mixed. Add the molasses mixture and dry mixture and mix until blended.
Pour the batter into each ramekin. Do not fill more than 1⁄2 way. Sprinkle the brown sugar evenly between each ramekin. Mix together your hot water and butter and pour evenly into each ramekin. Allow 1⁄2 inch of space at the top of each ramekin.
Place in the oven and bake for approximately 35 minutes or until a clean toothpick comes out of the cake. Top the cake with powdered sugar, cream, or ice cream, and serve warm.