Combine flour, sugar, and salt in a medium bowl. Add cubed cold butter to the dry mix and coat the butter cubes with flour. Then use a pastry cutter, fork, or your fingers to work the butter into the flour mixture until it’s in pea-sized pieces.
Combine water, apple cider vinegar, and ice in a separate bowl. Add the liquid to the dry stuff a tablespoon at a time until the dough just comes together with some crumbs on the edges. You should need about 1/2 cup of the liquid.
Shape the dough into two round discs, adding more liquid in small drops if needed to get the dough to stick. Once the dough is in a solid disc, wrap it in plastic wrap and store it in the fridge for at least an hour, but overnight is best.
When ready to make pie, Preheat oven to 425 degrees F.
Roll each pie crust out on a lightly floured surface until it’s in a rectangle that fits in your sheet pan with an inch or so overhanging around the edge. Repeat with second pie crust disc. Trim off about an inch thick strip from each piece which will be the dividers between the pies. Use a fork to crimp the pie crusts together in the sheet pan (trim the crusts if you have a lot of overlap but some is okay). Crimp around the edges as well. Carefully place the divider strips in the sheet pan and crimp them into place so they stand up.
Gently cover the entire crust with foil (sprayed with nonstick spray on the side touching the crust). Press the foil to shape the crusts and then fill each pie section with dried beans or pie weights.
Bake the crust at 425 degrees F. for 12 minutes. Then carefully remove the beans and foil.
For the fillings (do this while the crust rests in the fridge or bakes).
Peel apples, core them and slice into segments. Then toss with sugar, salt, cinnamon, flour, and lemon juice. Let drain in a colander until ready to use in the pie.
For the pumpkin, stir together all ingredients in a medium bowl. Whisk well to combine until the mixture is very smooth.
For pecan, melt butter, sugar, and corn syrup over low heat until it’s warm and the sugar is melted. Remove and let cool. Then add vanilla, orange zest, salt, and eggs.
Baking the Tri Pie
When the pie crust is done pre-baking, add each filling to a section of the tri pie. Add pecans to the pecan section after you pour the filling in. You can fill up each section almost to the top. You might have some filling leftover for the pumpkin and pecan sections.
Carefully transfer the tri pie to a 350 degree oven and bake for 45-50 minutes until each pie section is cooked through.
Let the tri pie cool for at least half an hour before slicing into it!