Rhubarb Compote Cake

Ingredients : 8 stalks rhubarb cut into 1/2-inch pieces 3 apples – peeled cored and diced ½ cup white sugar ¼ cup water ⅔ cup white sugar ¼ cup margarine 1 egg 1 teaspoon vanilla extract ¾ cup milk 1 ½ cups all-purpose flour 2 teaspoons baking powder ¼ teaspoon salt...