Preheat Oven to 350 degrees.

Brush egg yolk into bottom and sides of graham cracker crust

Let crust bake in oven 5 minutes, then remove and let cool while you prepare filling and topping. 

Peel apples and cut into slices approximately 1/4 inch thick. 

In a medium bowl, place melted butter, sugar, flour, cinnamon and nugmeg and combine. 

Add apple slices into the bowl and mix until well coated. 

Add the filling into the pie crust. 

Combine the flour, sugar, salt, brown sugar, and cinnamon. 

Cut your 5 tablespoons of chilled butter into small cubes. 

Mix butter cubes into the mixture. I found it easiest to use my hands and squeeze the butter into the sugar/flour/etc mixture. Keep going until the cubes of butter are well mixed into the mixture. The texture should be similar to clumpy sand. 

Spread crumble mixture over the top of the pie filling. 

Preheat oven to 400 degrees. 

Place pie tin on a cookie sheet and place in oven for 10 minutes.

Reduce heat to 350 degrees, and bake an additional 45 minutes. 

Let the pie cool for 45 minutes before serving.