Heat over to 425˚.
Line a baking sheet with parchment or silicone.
Prepare foil dome to cover the pie if it gets too brown.
Prepare the crust according to directions.
In a large bowl, combine the apples, sugar, lemon, tapioca, flour and cinnamon.
Place apple slices, by hand, in the pie shell layering the apple slices so there are no air pockets for the apples to collapse into. It should be densely layered.
FOR THE TOPPING:
Combine the dry ingredients and drizzle the butter over top.
Use a pastry blender or two forks to combine the crumbs.
Spoon the crumbs over the apples evenly.
Place pie on prepared baking sheet to catch sauce if it boils over.
Bake for 15 minutes at 425˚.
Reduce temperature to 350˚ and bake for an additional 45 minutes or until apples are bubbling around the edges. Cover if needed so check occasionally.
Test apples for doneness with a long knife through the center of the pie. The knife should slide in and out easily.
Remove from oven and cool completely before serving. This will allow the juices to thicken and the pie to stay together when cutting.