Place butter, flour, sugar, salt, crushed nuts (if using), and spice into the food processor and whisk until crumbled. This step can also be done in a medium bowl with a pastry blender.
Whisk in the egg and blend until a ball is formed. If dry, add a little cold water at a time. If too wet, add a little flour at a time until a smooth ball is formed.
Portion into the individual pie pans, or into one single pie pan and press the pie dough into place. Crimp the edges.Crust is now ready to fill.
Place in a 350 degree oven and bake with the filling of your choice until the filling is cooked and the crust is crisp, about 25 minutes for tarts and 45 for a larger pie.
Notes
If there is leftover dough, roll out on a floured surface and press into cookies. Bake at 350 for 12 minutes.