Cut each peach in half sideways, remove the peach pit. Rub exposed peach flesh with lemon juice. Place 1 tablespoon of jam into the center of each peach where the pit was removed ( you should have a nice pocket already there from the pit). For the topping: in a small bowl mix together flour, butter, brown sugar, oats, cinnamon and salt. Press this mixture on the top of each peach, covering jam. Place peach halves in a 9 inch baking dish. If need be, remove a small slice from the bottom of the peach to make it sit on the bottom of the baking dish without wobbling. Bake until top is golden brown and peach is tender, about 25 minutes. Check at 20 minutes for doneness.