Cut the butter and shortening into cubes and place in the freezer to get them really cold while you pull out the rest of your ingredients.
Place the flour, salt and sugar in a food processor. Pour 6 tablespoons of apple brandy (or your booze of choice) over ice to chill. Place the butter and shortening in the food processor, and pulse until it breaks up into small pea-sized chunks. Without scooping up the ice, add the liquor one tablespoon at a time to the mixture and pulse to combine. Once the dough starts to pull together into a mass, stop adding liquid and dump the dough out onto a piece of plastic wrap.
Divide 1/3 of the dough out for the topping and place in a medium bowl. Then shape the remaining dough into a disk, wrap well in plastic, and place in the fridge to chill for at least 30 minutes.
Break the divided dough into little pieces, then add the oats, almonds, brown sugar and cinnamon. Mix and crumble with your hands, then place in the fridge until ready to use.
For the Filling:
Place the lemon juice and zest in a large bowl. Peel and thinly slice all the apples (1/8- to 1/4-inch thick) tossing in the lemon juice as you add them to the bowl. Add the sugar, salt, cornstarch and spices to the apples and toss to coat.
Preheat the oven to 450 degree F and place the rack in the lowest position. Place a piece of plastic wrap (or foil) out on the counter. Flour the plastic wrap and place the chilled dough on the floured work surface. Flour a rolling pin and roll the dough out into a large round circle approximately 12 inches across. Carefully lift the plastic wrap and flip the dough circle over into a 9-inch deep-dish pie pan. Gently fit the pie dough down into the pie pan—don't stretch it. Then fold the rough edges under and pinch-crimp the edges with your fingers.
Scoop the apple filling into the pie crust. Shake a little so the apple slices settle into place. Then sprinkle the crumble topping over the apples, covering completely. Place the pie in the oven, and LOWER THE TEMPERATURE TO 375 DEGREES F. The extra heat from the beginning gives and crust a little head start in baking. Bake the pie for 60-80 minutes, until golden and bubbly. If the crumble topping starts to get too dark, loosely cover with foil while baking.
This is the hard part... DO NOT cut the pie until it has cooled down to room temperature. I know it smells amazing and is very hard to resist, but the filling needs time to settle and set, so it's not soupy. If you cut your pie too soon, it will fall apart.