Mix 1 cup brown sugar, flour, 3 tablespoons cocoa, baking powder and salt together in a mixing bowl. Stir in milk, margarine and vanilla extract. Spread over bottom of the crockpot or slow cooker.
In another bowl, mix together the remaining 3/4 cup brown sugar and 1/4 cup cocoa. Sprinkle evenly over the first mixture. DO NOT STIR.
Pour in boiling water. DO NOT STIR.
Cover and cook on HIGH for 2 to 3 hours until wooden pick inserted comes out clean.
Serve warm with ice cream or whipped cream.Makes 12 Source: