In a large mixing bowl, stir together the flour, salt, and brown sugar.
Add the cold shortening and butter. Mix with a pastry cutter or your fingers until the mixture looks crumbly.
Gradually add cold water and blend just until a dough forms.
Divide the dough in half, shape each into a log, wrap in plastic, and chill in the refrigerator for at least 1 hour.
In a microwave-safe measuring cup with a spout, melt the butter.
Whisk in the corn syrup, maple syrup, vanilla, and eggs until the mixture is smooth.
Preheat the oven to 425°F (220°C).
Remove one dough log from the fridge. Cut it into 12 even pieces and roll each piece into a circle about 1 cm thick.
Press each dough circle into a muffin tin to form the tart shells.
Divide the golden raisins evenly among the tart shells, placing them at the bottom.
Pour the filling over the raisins in each tart, filling each about three-quarters full.
Repeat with the second dough log to make 12 more tarts.
Bake for 15 minutes or until the crusts are lightly golden and the filling is bubbling.
Let the tarts cool in the tin before removing carefully.