Divide the butter into two parts:
5 Tblsp - Cut into 3/4 inch cubes, place in the refrigerator, for at least 30 minutes
3 Tblsp - Cut into 3/4 inch cubes, place in the freezer for at least 30 minutes.
Place the flour with the salt and B.Powder in a bowl of a standing mixer using the paddle attachment mix on low speed for a few seconds.
Add the first large amount of butter into the flour mixture and mix until the butter is peas size.
Continue with the smaller amount of butter and mix for about 30 seconds.
Add 2 1/2 TBS of ice water and the cider vinegar than turn off the mixer and continue to mix with your hand just until the dough comes together and can be formed into a disk.
Warp the dough with plastic food wrap and place it in the refrigerator for an hour or overnight.
When ready, roll the pastry into 1/8 inch thick or less and large enough to cut a 13-inch circle.
Transfer the pastry to the pie pan and cut the excess dough, use it to cut the leaves. If you choose to create a different design, tuck the excess dough under itself and form the preferred design.
Place the pastry in the refrigerator while you make the filling.
Preheat the oven to 375F. Set an oven rack on the lowest level and place a cookie pan (or plan to bake on the oven floor).
Process the gingersnaps and pecan until finely ground and layer the mix over the bottom of the pie crust pressing them into the dough using the back of a spoon going about 1/2 inch up the sides.
In a small heavy saucepan, stir together the pumpkin puree, sugar, spices and salt and cook over medium heat. When simmering, reduce to low heat and keep stirring for 3-5 minutes until thick and shiny.
Add the mixture to the food processor and process for 1 minute. Pour the milk, heavy cream, and eggs one at a time. Add the Vanilla extract
Pour the mixture into the pumpkin shell and set it on the cookie sheet.
Bake the pie for 50-60 minutes or until the sides of the filling is puffed and the center shakes like Jelly when moved.