Combine apple slices and orange juice in a large bowl; add 1/3 cup sugar and next 3 ingredients, stirring well. Spoon mixture into an 11- x 7- x 1 1/2-inch baking dish; set aside.
Combine remaining 1/3 cup sugar, flour, baking powder, and salt; cut in margarine with a pastry blender until mixture resembles coarse meal. Add milk; stir with a fork just until dry ingredients are moistened.
Drop batter by 8 large spoonfuls over apple mixture; sprinkle 2 teaspoons sugar over cobbler. Bake at 375° for 35 minutes. Serve warm or at room temperature.