Preheat oven to 350°In a large bowl mix flour, brown sugar, and butter with a mixer until small pebbles formTake out 1 Cup of mixture and set asideIn another bowl combine molasses, hot water, and baking soda (add baking soda to water then to molasses to create a reaction)Add wet ingredients to dry and mixPlace batter in a 9X13 greased panSprinkle flour, sugar, and butter mixture that was set aside from earlier on top of cakeBake at 350° for 40-45 minutes