In a small saucepan, combine brown sugar, cornstarch and water until smooth. Add peaches; bring to a boil. Cook and stir for 2 minutes. Reduce heat to low; stir in butter and lemon juice. , For topping, combine flour, sugar, baking powder and salt in a bowl. Stir in milk, butter and orange zest. Transfer hot peach mixture to an ungreased 2-cup baking dish. spoon topping over peaches. Bake, uncovered, at 400° until golden brown, about 25 minutes.