In a mixing bowl, sift the flour, salt and sugar together.

Using a pastry blender or your hands, cut the butter into the flour mixture until it resembles coarse meal. Add the cold water a bit at a time until the dough just starts to hold together.

Press the dough together and shape it into a disk. Wrap the dough in plastic wrap and refrigerate for at least 30 minutes.

Roll out the dough to about 1/8 inch thick and cut 4-inch circles. Press dough in greased muffin cups trying not to stretch the dough too much.

Preheat the oven to 400°F.

In a large bowl, mix together the butter, brown sugar and corn syrup. Stir until butter is creamed and sugar is dissolved.

Add the eggs, vanilla extract and salt. Optionally add raisins. Mix well.

Fill each tart shell with the butter filling. Each tart should hold about 1 tablespoon of filling, be careful not to overfill!

Bake for 15-20 minutes. The filling should be lightly browned and still bubbling.

Let the tarts cool in the pan for about 10 minutes before transferring them to a cooling rack.