In a small bowl beat egg. Set aside.
Add shortening and flour to a large bowl.
Work shortening into flour with a pastry cutter until mixture has a crumbly texture resembling cornmeal.
Add beaten egg, cold water and white vinegar to shortening mixture.
Stir until just incorporated.
Cover surface with plastic wrap.
Place dough on wrap and use rolling pin to flatten to about 1/2".
Refrigerate for at least 20 minutes.
In a large bowl, combine 1/2 cup sugar, 1/2 cup brown sugar, 1/4 cup flour and 1 teaspoon cinnamon and 1/4 teaspoon nutmeg. Mix well.
Core, peel and slice apples into about 1/4" slices.
Add the apples and cider vinegar to the bowl of sugar and spices. Toss to coat. Set aside.
Preheat the oven to 425.
Flour a work surface.
Roll out pie crust on prepared surface.
Place in pie pan and pinch edges.
Line a baking sheet with aluminum foil to catch any spillover during baking and place in bottom third of oven.
Put apples in crust and dot top with pieces of butter.
Bake for 20 minutes.
In a large bowl, add 1/2 cup flour, 1/2 cup sugar, 1/2 cup brown sugar, Quick Oats, 3/4 tsp cinnamon and 1/4 tsp nutmeg. Whisk together.
Add cold butter and work with a pastry cutter until fully incorporated.
Crumble so pieces are no larger than pea sized.
Remove pie from oven and top with struesel mixture.
Add pie ring or loosely cover outer edge of crust with aluminum foil.
Reduce temperature to 375.
Return pie to oven to cook for about 50 minutes more (when crust is golden and filling is bubbling).
Allow to cool before serving.