1. Preheat the oven to 375 degrees F. Refrigerate the pie crust (in the pan) while preparing the filling/topping.
2. FOR THE APPLE FILLING, in a large bowl, add the sliced apples. Add in the brown sugar, flour, lemon juice, cinnamon, nutmeg and salt. Stir the mixture carefully (to avoid breaking apart the apples) until it is evenly combined. Set aside.
3. FOR THE CRUMBLE, in a medium bowl, mix together the flour, brown sugar, cinnamon and salt. Drizzle the melted butter over the ingredients and mix with a spoon or spatula until the mixture is crumbly (sometimes I ditch the spoon and get my hands right in there to get it mixed).
4. Fill the chilled pie crust evenly with the apple mixture – if the apples have released a lot of liquid, do your best to transfer just the apples and thick, sugary mixture to the pie plate and leave most of the thin liquid in the bowl (once the apples are in the pie plate, I drizzle about 2-3 tablespoons of leftover liquid over the pie and discard the rest; don’t panic if there isn’t much liquid at all).
5. Place the pie on a foil-lined, rimmed baking sheet. Spread the crumble topping evenly over the top of the apples.
6. Bake for 45-50 minutes (covering loosely with foil the last 10-15 minutes, if the pie crust or crumble is overly browning) until the filling is hot and bubbling and the crust is evenly browned.
7. Let the pie cool to room temperature (or just slightly warm) before serving. It will thicken and set up as it cools.

Recipes Source: http://mysan-grahams.com.ph/recipes/list