Cut the cores out of the apples, and cut into thin slices. Toss apples with the lemon juice. Spread half of them into a large pan – 13 by 9 inches or larger.
Toast the sunflower seeds and nuts together in a pan over medium heat until they are lightly browned and fragrant, being careful not to let them burn.
Melt the butter and honey together. Mix the oats, flour, nuts and seeds, salt and spices together. Add the melted butter and honey, stirring until all the dry ingredients are moist. Crumble half of this mixture on top of the apples in the pan. Cover with the remaining apples and the rest of the topping.
Pour apple cider or orange juice over the top. Bake 40-45 minutes, uncovered, at 375°. Cover if it crisps too quickly.
Serve with ice cream or yogurt for a delicious fall and winter treat.