In a mixing bowl, combine the all-purpose flour and a pinch of salt. Cut in cold unsalted butter until resembling coarse crumbs, about 5-7 minutes. Gradually add iced water, mixing until the dough holds together. Wrap in plastic wrap and refrigerate for 30 minutes.

Preheat your oven to 350°F (175°C) and position the rack in the center.

Roll the dough out to about 1/8 inch thick. Cut out circles to fit into greased muffin tins. Press the dough circles into the cups.

Whisk together large eggs until well beaten. Mix in brown sugar, corn syrup, and vanilla extract until smooth. Fold in chopped pecans.

Spoon filling into each crust, filling about three-quarters full. Bake for 20-25 minutes, or until filling is set and crust is golden brown.

Let the pies cool in the muffin tin for 10 minutes before transferring to a wire rack to cool completely.