Peel, core and slice the apples.
Melt the butter in a Dutch oven, add lemon juice, granulated sugar and brown sugar.
Cook the apples over low/medium heat.
Add cornstarch slurry (cornstarch & cold water mixed) and cook for about 10-15 minutes, until slightly thickened.
Stir with a spoon occasionally to prevent burning.
Remove from the heat, add cinnamon & nutmeg.
Let pie filling cool completely before assembling. Refrigerate overnight.
Prep pie dough and put in the refrigerator to chill for a few hours or overnight.
Roll out pie crust on a lightly floured surface, slightly larger in diameter than your baking dish.
Add the apple pie filling to the unbaked pie shell.
Roll out the top crust.
Place the top pie crust over the apple filling.
Fold over, lightly press down on the filling, trim, and crimp edges with your fingers.
Place pie on a half sheet pan lined with parchment paper.
Use a sharp knife to cut vents - which helps steam escape.
Beat together with a fork: 1 large egg, 1 teaspoon water & and a pinch of salt.
Brush on the pie & sprinkle with sugar before baking.
Bake in a preheated 400-degree F oven for about 1 hour, or until the crust is golden browned & pie filling bubbling up.
Let cool for 2-3 hours before slicing!
