01 - Preheat oven to 350°F. Generously grease a 12-cup mini muffin pan with butter or cooking spray.
02 - Combine flour and salt in a mixing bowl. Cut in cold butter using a pastry cutter or fingers until mixture resembles coarse crumbs. Sprinkle cold water over mixture, 1 tablespoon at a time, tossing gently with a fork until dough holds together when pressed.
03 - Roll dough on 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, extending slightly above the rim.
04 - Whisk together brown sugar, corn syrup, melted butter, egg, vanilla extract, and salt until completely smooth and well combined. Fold in chopped pecans until evenly distributed.
05 - Spoon filling into prepared crusts, approximately 1 tablespoon per mini pie. Bake for 22-25 minutes until filling is set and crust is golden brown.
06 - Let pies cool in pan for 10 minutes before carefully removing. Transfer to wire rack to cool completely. Serve plain or topped with whipped cream.