
In a large bowl, whisk together the flour and salt. With a pastry cutter, cut in the butter until only pea sized pieces remain. Add cold water until the dough is shaggy, form into a disc, cover and chill for at least 2 hours.
Roll the chilled dough to ⅛” thickness, cut into 4” circles, and press into a muffin tin. Chill again while preparing the filling.
Preheat the oven to 400°F (200°C).
In a bowl, whisk together the corn syrup, brown sugar, butter, egg, vanilla, cornstarch, cinnamon, salt, and nutmeg until smooth.
If using raisins, distribute them in tart shells, then fill with the syrup mixture halfway.
Bake for 5 minutes at 400°F, lower to 350°F, and bake for an additional 15-20 minutes until filling is bubbling.
Allow to cool for at least 15 minutes before removing from the pan.