Prepare the pastry: In a bowl, mix flour and salt. Cut in the butter using a pastry cutter or fork until the mixture resembles coarse crumbs.

Gradually add ice water, 1 tablespoon at a time, mixing until the dough holds together. Form into a disc, wrap in plastic, and chill for 30 minutes.

Preheat oven to 375°F (190°C). Roll out the dough on a floured surface and cut into 3-inch circles. Press into a muffin tin and refrigerate while preparing the filling.

Make the filling: In a bowl, whisk together brown sugar, corn syrup, melted butter, egg, vanilla, vinegar, and salt until smooth. Stir in raisins or pecans if using.

Fill each tart shell 2/3 full with the mixture.

Bake for 15-20 minutes, until the filling is set but still slightly gooey.

Let cool for 5 minutes in the pan before transferring to a wire rack. Enjoy!