I've made this in a pie plate, but I've also made it in an 8x8 square pan and I've even doubled the recipe and made it in a 13x9 pan. It's very versatile and everyone who tries it loves it. It's the ONLY apple pie I like.
Toss apples with Cinnamon Sugar and Walnuts (if using), then pour into a pie plate.
In a separate bowl, thoroughly mix together sugar with the flour, butter, and egg. Spread evenly over the top of the pie.
Bake in preheated oven until the apples have cooked and the topping is golden brown, about 40-45 minutes. Store covered in the refrigerator. This pie is best served warm topped with ice cream and a drizzle of caramel sauce!