Fill a large bowl with ice water and squeeze the juice from one lemon into the water. Peel and core the apples and place them in the lemon water (ideally, the water should prevent the fruit from turning brown).

Once all of the apples are cored and peeled, remove them from the water bath, dump out the water, and dry the bowl. Add the 1/4 cup lemon juice to the bowl. Begin slicing the apples into 1/4-inch wedges, and then slice the wedges or cut the apple into chunks. Place the wedges in the bowl with the lemon juice as you work, tossing the wedges in the juice to coat.

Once all of the apples are cut into wedges, add the granulated sugar, cinnamon, nutmeg, salt, and arrowroot, and using your hands, or a wooden spoon, toss the ingredients together until thoroughly combined. set aside.

Place the butter-y brown sugar crumble ingredients in a medium-sized bowl and, using your fingers, smoosh all of the ingredients together until you have a bowl of crumble-y crumb bits, some small, and some larger. Set aside

Place one rolled out sheet of dough in the bottom of your half sheet pan as per the pie crust instructions and add the apple filling. Dot the top of the filling with the butter-y brown sugar crumble, and continue to follow the pie crust instructions for prepping and baking your pre-baked pie.