Preheat oven to 350 degrees. In a medium saucepan, melt the butter and add the lemon peel and fruit. Add cornstarch and 3/4 cup of sugar and cook over medium heat, stirring constantly, until thickened, 6-8 minutes. Pour into 1 1/2 qt. Shallow baking dish; let stand while making topping. Sift flour, remaining 3/4 cup of sugar, baking powder and salt into mixing bowl. Add milk, shortening, vanilla and egg. Beat at medium speed for 2-3 minutes. Spoon over fruit in baking dish. Bake about 40 minutes.