In a large bowl, combine the flour, sugar, and salt. Pour over the oil and mix until the flour is coated. It will look crumbly.

Add the butter and cut or mix until small pieces of butter are still visible.

Stir the water and vinegar together and add all at once to the flour mixture. Mix until the dough just comes together. Turn the dough out and gently work until it comes together. Cut dough in half and wrap each piece in plastic wrap. Chill for at least an hour.

To make the pie, preheat your oven to 400*. Set out your pie dough for 15 minutes before rolling.

Toss the apples with lemon juice. Add half of the apples to a sautés pan and cook over medium heat until most of the juices cook out and the apples soften, about 10 minutes. Use a slotted spoon and add the cooked apples to the uncooked ones. Add both sugars, cinnamon, allspice, nutmeg, and salt. Stir until combined.

On a floured surface, roll the first dough to a little less than a 1/4 inch thick. Dust a 9-inch glass pie plate with flour. Transfer the dough to the pie plate. Sprinkle the bottom with oats. Add apple filling to the pie crust and dot with butter.

Roll out second dough to the same thickness, drape over apples. Trim excess dough with scissors or a knife. Tuck under and then pinch to create a fluted edge.

Whisk egg and 2 tablespoons water. Brush over pie, sprinkle with cinnamon and sugar. Use scissors to snip pie crust to allow steam to escape.

Place the pie on a parchment lined rimmed baking sheet. Bake at 400° for 10 minutes, then reduce temperature to 375° and bake for another 40 to 50 minutes. The crust should be golden and the filling should bubble out of the vents. Cool for at least 2 hours before slicing.