Preheat oven to 375°F and grease a 12-cup muffin tin thoroughly with butter or cooking spray.

In a large mixing bowl, combine flour and salt. Cut in cold butter using a pastry cutter or fork until mixture resembles coarse crumbs.

Add ice water one tablespoon at a time, mixing gently until dough just comes together. Form into a disk, wrap in plastic, and refrigerate for 15 minutes.

While dough chills, prepare filling by whisking together brown sugar, melted butter, eggs, vanilla extract, and a pinch of salt until smooth and well combined.

Roughly chop pecans and toast them in a dry skillet over medium heat for 3-4 minutes until fragrant. Set aside to cool.

Roll out chilled dough on a floured surface to 1/8-inch thickness. Cut out 12 circles using a 4-inch round cutter, re-rolling scraps as needed.

Press dough circles into muffin cups, ensuring they come up the sides. Trim any excess hanging over the edges.

Divide toasted pecans evenly among the pastry shells.

Carefully pour brown sugar filling over pecans in each tart, filling about three-quarters full.

Bake for 20-22 minutes until filling is set and pastry edges are golden brown.

Allow tarts to cool in pan for 10 minutes, then carefully remove using a butter knife to loosen edges. Transfer to a cooling rack.

Serve warm or at room temperature.