Mix the apple slices, sugar, lemon juice, cornstarch, vanilla, nutmeg, cinnamon, and salt together in a large bowl.
Add mixture to your pie dough already in the pan. Brush the hanging edges of the dough with water and carefully cover it with the rolled-out top crust as you pinch the edges together. Be sure to turn them under all around the pie to make a thick edge.
To decorate the rim all around, press it with the back of a fork, or just pinch it to seal. Use scissors to cut off a few V-vents in the center of the pie.
Slide the ready-to-cook pie into the brown paper bag and fold the top down. Staple it shut so it does not open and places it on a baking sheet pan. Bake for an hour.
After an hour, remove the pie from the oven and cut a large circle on the top of the bag. Put the pie back into the oven and bake for about 15 minutes, until the crust is golden brown.
Allow it to cool down for 30 minutes before serving.
Serve warm or at room temperature.