In a food processor pulse together flour, salt, and granulated sugar. Pulse in butter, creating both large and small crumbs (the small crumbs should resemble cornmeal). Pulse in ice water, one tablespoon at a time, until mixture clumps together.
Turn dough out onto plastic wrap. Pat together into a rectangle, then divide into thirds. Pat one third into a circle, and wrap in plastic. Combine the other thirds together, pat into a circle, and wrap in plastic. Place both circles in the refrigerator to chill.
Meanwhile, put apples in a colander set over a large bowl. Sprinkle brown sugar, cinnamon, and vanilla over the apples and toss to coat. Let rest 15 minutes.
Preheat oven to 350°F.
Remove larger disk of dough from the fridge. Sprinkle a work surface with flour and roll dough out to approximately 9 inches diameter. Place dough in a 10-ounce ramekin dish, fixing tears as needed and making sure the dough reaches the bottom edges of the dish. There will be excess dough hanging over. Place the ramekin in the fridge, and remove the smaller disk.
Roll out smaller disk to approximately 5 inches diameter. Using a small cookie cutter, cut out a shape in the center or off-center. (Alternatively, you can just vent the dough with a knife once the pie is filled.) Save the cut-out.
Working quickly, set the colander with apples in the sink, and whisk the clear jel or cornstarch into the juices that accumulated at the bottom of the bowl, leaving no lumps. Pour the apples into the bowl and toss with the thickened mixture.
Remove the ramekin from the fridge and pour the apples into the prepared dough. Brush beaten egg along the top edge of the dough, then place top crust on. Pinch crusts together to seal, and remove any excess dough. Brush more egg on the top crust, and sprinkle with sugar if desired.
Set ramekin on a baking sheet and bake for 40 minutes, until crust is nicely browned and pie is bubbly. Let cool completely before serving.