01 - Preheat oven to 350°F. Generously grease a 12-cup mini muffin pan with butter or cooking spray.
02 - In a medium bowl, whisk together flour and salt. Cut in cold butter using a pastry blender or two forks until the mixture resembles coarse crumbs. Gradually add cold water, 1 tablespoon at a time, mixing gently until the dough just comes together into a ball.
03 - Roll out the dough on a lightly floured surface to about 1/8 inch thickness. Using a 3-inch round cookie cutter, cut twelve circles. Gently press each circle into the wells of the mini muffin tin, easing the dough up the sides.
04 - In a separate bowl, whisk together brown sugar, corn syrup, melted butter, egg, vanilla, and salt until completely smooth and well combined. Stir in the chopped pecans until evenly distributed.
05 - Spoon the pecan filling evenly into the prepared crusts, about 1 tablespoon per pie. Bake for 22-25 minutes, or until the filling is set and the crust is golden brown.
06 - Let the pies cool in the pan for 10 minutes before carefully removing them. Transfer to a wire rack to cool completely. Serve plain or topped with whipped cream if desired.