1. Heat oven to 375°F. Grease 8-inch square baking pan.
2. Combine baking mix and cocoa in medium bowl; stir in 1 cup sweetened condensed milk, 1/4 cup syrup and vanilla until blended. Spoon evenly into prepared pan.
3. Combine remaining sweetened condensed milk, remaining 1/2 cup syrup and water in small bowl. Pour liquid mixture carefully over top of mixture in pan; do not stir.
4. Bake 25 to 30 minutes or until center is set and cake begins to pull away from sides of pan. Let stand 10 minutes; spoon into dessert dishes, spooning pudding from bottom of pan over top. Serve warm; garnish with whipped topping, if desired. Cover; refrigerate leftover dessert. 6 to 8 servings.