Cut the apples in half around the middle of the apple. Using a melon baller, scoop out the core of each apple half creating a round whole in the apple halves. Rub the inside of the hole you created and any other part of the apple without the peel on it with lemon juice. Place 1 Tablespoon of jelly, jam or preserves into each hole.For the Topping:In a small bowl mix the flour, butter, brown sugar, cinnamon and salt.Using a pastry blender cut the butter into the mixture until it's well combine. Add the oats to the bowl. Using your fingers, rub the oats into the mixture until they are well combined. Press the topping onto the top of each apple, covering the jam. Place the apples in a baking dish with about 1/4 of an INCH of water in the pan. Bake until top is golden brown and apple is tender, about 35 - 40 minutes.