Preheat your oven to 400°F (200°C).
Pour the apple filling into your prepared crust, piling it a bit higher in the middle for that classic dome shape. Dot the top with those tiny bits of butter. This step might seem small, but it adds that rich, luscious flavor we all love.
Roll out your second dough disc, just like you did with the first, and gently lay it over the apples. Trim the edges, leaving about an inch overhang. Tuck that top crust under the edge of the bottom crust and crimp it however you like fancy fluted edges or just a simple fork press.
Use a sharp knife to make a few slits or decorative vents on top to let the steam escape. Trust me, you don’t want a pie volcano.
Brush the top with the beaten egg and sprinkle it with a little sugar for that beautiful golden, sparkly finish.