Toss the apple slices in lemon juice and arrange half of them in a lightly greased 9-inch baking dish.

In a medium bowl, mix flour, granulated sugar, brown sugar, cinnamon, and apple pie spice. Add cold butter and blend using a pastry blender or two forks until the mixture resembles coarse crumbs.

Sprinkle half of the crumb mixture over the apples in the dish. Layer the remaining apples and top with the remaining crumb mixture.

Bake in a preheated oven at 350°F for about 45 minutes, or until the topping is golden brown and the apples are tender.

Serve warm. Top with vanilla ice cream if desired.