Cream together butter and brown sugar.
Stir in molasses, egg, and vanilla extract.
Mix in flour, baking soda, ground cinnamon, ground ginger, ground cloves, and salt.
Stir in boiling water.
Pour into 9x9" baking pan and bake until a toothpick inserted in the center comes out clean or with a few moist crumbs.
Top with whipped cream (if desired) and enjoy!