Preheat the oven to 325 degrees
Butter a 9" spring form pan
Prepare the dough
In a mixing bowl combine the flour, sugar, salt , and lemon zest.
With the mixer running add in the butter and then te egg until it forms wet crumbs.
Place the dough on a lightly floured surface and knead together.
Reserve 1/3 of the for the top of the tart
Roll out the remaining dough into a large 16" round and if this doesn't work because it is falling apart simply press the dough into the buttered spring pan and work the dough up the sides.
Assembly:
Put the apple slices into a bowl and add in the sugar and cinnamon and toss all together
Sprinkle the bread crumbs on the bottom of the tart shell and then pour the apples inside.
Roll out the remaining dough into a round.
Once again the dough will break up just make chunks of dough around the top or if you can keep the dough together you can try to slice it with a pizza cutter and make a lattice design.
Brush the top of the tart with the egg wash and then sprinkle on some granulated sugar.
Bake for 1 1/4 hours but check at around 1 hour. You want it to be tender and the juices bubbling.
Cool completely in the pan.
Take a knife around the edge of the spring form pan, then release it.
Savor this apple delight!