Preheat oven to 400 degrees F. In a 9 by 12 baking dish, combine apples, lemon juice, cinnamon, nutmeg and sugar. In a small bowl, mix flour or graham cracker crumbs, brown sugar and butter together using the tines of a fork and your fingers, working until even, small crumbles form. Sprinkle topping evenly over apples and bake 15 to 20 minutes until apples are just tender and topping is golden brown. Top dishes of apple crisp with small scoops of vanilla ice cream. YUM!