Preheat oven to 400 degrees. Spray 9-inch pie pan with non-stick cooking spray, and place unbaked pie crust in the pan.
Arrange apple slices in an unbaked pie crust.
Mix ½ cup sugar with ¾ teaspoon ground cinnamon, and pour over the apples.
Next, mix 1/3 cup sugar with flour and then cut the butter into the flour/sugar until crumbly. Spoon crumbles over the pie, and bake for 35 to 40 minutes, or until apples are soft and the top is lightly browned.