Preheat oven to 325?F
Spray 8-inch-square baking dish with nonstick cooking spray; set aside
In large bowl, combine water, rolled oats and 1/4 cup plus 2 tablespoons margarine; cool to lukewarm
With electric mixer at medium speed, beat in sugar, 6 packets Sweet One?, 2 tablespoons molasses, egg and vanilla
In small bowl, stir together flour, cinnamon, baking powder, baking soda and salt; stir into oatmeal mixture until well blended
In large metal bowl with electric mixer at high speed, beat egg whites and cream of tartar until stiff peaks form; fold into batter
Spoon batter into prepared pan
Bake in center of over 25 to 30 minutes or until wooden pick inserted in center comes out clean
Cool on wire rack
Prepare topping: Preheat oven to broil
In small saucepan over medium heat, cook 2 tablespoons margarine, milk, 1-1/2 teaspoons molasses and 2 packets Sweet One? 2 to 3 minutes or until bubbly and slightly thickened
Stir in Walnuts and coconut, if desired
Spread on cake
Broil 3 to 4 inches from heat source 30 seconds or until nuts begin to brown
Cool on wire rack