Preheat the oven to 425 degrees F (220 degrees C). Arrange pastry in the bottom of a 9-inch pie pan. Place apples in crust.
Mix 1/2 cup sugar, 2 tablespoons flour, and cinnamon together in a bowl; pour over apples in crust. Sprinkle lemon juice on top.
To make the crumble topping: Place 1/2 cup sugar and 1/2 cup flour in a bowl. Cut in cold butter with 2 knives or pastry blender until the mixture resembles coarse crumbs; sprinkle crumble mixture evenly over apples. (Or you could just melt the butter and stir it all together which I do most of the time)
Take two 15-inch pieces of parchment paper and enclose pie; fold edges up 3 times. Place on a baking sheet.
Bake in the preheated oven, without opening the parchment, for 1 hour. Remove from oven, split parchment open, and cool pie on a wire rack. Serve warm, or at room temperature.