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 cubed butter using a pastry cutter or fingers until mixture resembles coarse crumbs. Sprinkle cold water over the mixture, 1 tablespoon at a time, mixing gently until dough just comes together.
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, ensuring even coverage up the sides.
04 - Whisk brown sugar, corn syrup, melted butter, egg, vanilla, and salt in a medium bowl until completely smooth. Fold in chopped pecans until evenly distributed.
05 - Divide filling evenly among prepared crusts, using about 1 tablespoon per mini pie. Fill each cup nearly to the top, leaving slight space for filling expansion during baking.
06 - Bake for 22-25 minutes until filling is set and crust is golden brown. The centers should still have slight jiggle but not be liquid.
07 - Let pies cool in pan for 10 minutes. Carefully loosen edges with a small knife and remove to wire rack. Cool completely before serving. Add whipped cream if desired.