Preheat your oven to 425°F (220°C). This ensures that your pie crust will bake up golden and flaky.

In a large mixing bowl, combine the sliced apples, granulated sugar, brown sugar, cinnamon, nutmeg, salt, and lemon juice. Toss until the apples are well coated in the mixture, allowing them to release their juices.

Add the caramel sauce to the apple mixture and stir gently to incorporate, creating a rich and gooey filling. Set aside for about 15 minutes to let the flavors meld.

Roll out your pie crust and fit it into a 9-inch pie pan, ensuring there are no cracks. Leave a bit of overhang to crimp later.

Pour the apple and caramel filling into the prepared pie crust, spreading it evenly. Dot the filling with the butter pieces to add richness and depth.

Cover the pie with the second pie crust, crimping the edges to seal the filling inside. Cut a few slits in the top crust to allow steam to escape. Brush the top with the beaten egg for a beautiful golden finish.

Place the pie on a baking sheet to catch any drips and bake in the preheated oven for about 45-50 minutes, or until the crust is golden brown and the filling is bubbling.

Once baked, remove the pie from the oven and let it cool for at least 30 minutes. This cooling time allows the filling to set up a bit more.

Before serving, drizzle extra caramel sauce over the top for an added touch of decadence. Slice and enjoy your deliciously rich caramel apple pie!