01 - Preheat oven to 350°F. Lightly grease a 12-cup mini muffin pan with cooking spray or butter.
02 - Combine flour and salt in a mixing bowl. Cut in cold butter using a pastry blender or two forks until mixture resembles coarse crumbs. Sprinkle cold water over the mixture, 1 tablespoon at a time, tossing gently with a fork until dough holds together when pressed.
03 - Roll dough on a lightly floured surface to 1/8-inch thickness. Cut twelve 3-inch circles using a round cookie cutter. Gently press each circle into the wells of the mini muffin tin, easing dough into bottom and up sides.
04 - Whisk brown sugar, corn syrup, melted butter, egg, vanilla, and salt in a medium bowl until completely smooth and well combined. Fold in chopped pecans until evenly distributed.
05 - Divide filling evenly among the prepared crusts, using about 1 tablespoon per mini pie. Fill each crust to just below the rim to prevent overflow during baking.
06 - Bake for 22-25 minutes until filling is set and crust is golden brown. The centers should still have a slight jiggle but not be liquid.
07 - Let pies cool in the pan for 10 minutes. Carefully run a small knife around edges to loosen, then remove to a wire rack to cool completely. Serve plain or topped with whipped cream.