In a food processor, pulse several times to combine the all-purpose flour, and 1/2 tsp each salt and sugar.
Add the cold unsalted butter, cut into small pieces. Pulse until mixture resembles coarse meal, with a few pea size pieces remaining.
Add 6 tblsp ice water; pulse until dough is crumbly but holds together when squeezed (if needed, add up to 2 more tblsp ice water, 1 tblsp at a time). Do not overmix.
Turn out onto work surface; knead once or twice, until dough comes together. Split the dough into 3 equal pieces. Flatten each piece of dough into a disk, wrap in plastic, and refrigerate at least 1 hour.
Place the dough on a floured piece of parchment or waxed paper. Using the knuckles of your hand, press edges of dough to help prevent cracking when you roll it out. Repeat for each piece of dough.
Roll the dough to a 14-inch round. Using parchment paper, lift and wrap the dough around the rolling pin, being careful to unroll over a 9-inch pie plate. Fit it into the bottom and along the sides of the plate, being careful not to stretch or tear dough. Repeat for each piece of dough.
With a paring knife, trim the dough 1" over the plate then fold under and seal to form a rim. Crimp the rim with a fork or your fingertips. Prick bottom of pie dough all over with a fork. Repeat for each piece of dough. Refrigerate for 1 hour.
Boil or bake potatoes until tender.
Remove the skin and discard, place in a mixer and blend until smooth.
Pre-heat oven to 365˚F.
Add the melted butter, sugar, nutmeg, cinnamon, and salt. Combine well.
Add the eggs, one at a time and mix well in between each egg.
Add the flour, buttermilk, vanilla, lemon extract and mix well.
Fill each of your pies with 1/3 of the pie filling.
Bake for about 1 hour or until the center of the pie is set.
