1. Preheat your oven to 375°F (190°C).
2. Roll out one of the pie crusts and gently place it into a 9-inch pie dish, pressing it against the bottom and sides.
3. In a large bowl, combine the sliced apples, sugar, flour, cinnamon, nutmeg, and salt. Mix well until all the apples are evenly coated.
4. Pour the apple mixture into the prepared pie crust, spreading it out evenly. Dot the top of the apple filling with small pieces of butter.
5. Roll out the second pie crust and place it over the apple filling. You can either create a lattice pattern or simply cover the pie with the whole crust, cutting a few slits to allow steam to escape.
6. Trim the excess pie crust from the edges and crimp them to seal the pie. Brush the top crust with the beaten egg and sprinkle some sugar on top for a nice golden color.
7. 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 apple filling is soft and bubbly.
8. Once baked, remove the pie from the oven and let it cool on a wire rack for at least 1 hour before serving. This will allow the filling to set and make it easier to slice.
9. Serve the soft apple pie warm or at room temperature, and you can enjoy it on its own or with a scoop of vanilla ice cream or a dollop of whipped cream.
Remember, this is a basic recipe, and you can always add your own variations or personal touches, such as adding raisins, lemon zest, or a streusel topping. Enjoy your soft apple pie!