Preheat oven to 350°.
In a bowl mix together the apples, cinnamon, nutmeg, lemon juice and brown sugar.
Butter or oil an 8 x 8-inch baking pan. Put apple mixture in it and set it aside.
In another bowl mix the oats, sugar, flour, cinnamon and bits of margarine or butter. Rub mixture with your fingers until crumbly.
Sprinkle the oat mixture evenly on top of the apples.
Bake for 40-45 minutes, until fruit is bubbling and topping is golden brown.