This is so easy and so good warm – never mind the ice cream!
1-3/4 cups brown sugar, packed
1 cup all-purpose flour
1/2 cup plus 3 tablespoons unsweetened cocoa
2 teaspoons baking powder
1/2 cup skim milk
2 tablespoons unsalted butter, melted
1/2 teaspoon vanilla
1-3/4 cups boiling water
Mix 1 cup brown sugar, flour, 3 tablespoons cocoa and baking powder in a mixing bowl. Stir in milk, butter and vanilla. Spread mixture over the bottom of a crockpot. In another bowl, mix together 3/4 cup brown sugar and 1/2 cup cocoa. Sprinkle mixture evenly over the mixture in the crockpot. Do not stir. Pour in the boiling water. Do not stir. Cover and cook on high 2 to 3 hours, or until a toothpick inserted comes out clean. Serve warm with ice cream or whipped topping if desired.