In a large bowl, mix chocolate milk, melted butter and vanilla until well blended. In another bowl, whisk flour, sugar, baking powder and salt; gradually mix into chocolate milk mixture. Stir in chocolate chips. Spread into a greased 3- or 4-qt. slow cooker., For topping, in a small saucepan, combine soda and sugars. Cook and stir over medium heat until sugar is dissolved; remove from heat. Stir in dark chocolate chips, jam and molasses; pour over batter., Cook, covered, on high until a toothpick inserted in center comes out clean, 2 to 2-1/2 hours. Serve with whipped cream and strawberries.