Line tart tins with pastry. Sprinkle 6-8 raisins into each tart shell.
Let butter cool to room temp, then add the remaining ingredients. Stir until smooth.
Spoon into unbaked tart shells, filling about 2/3 full.
Bake at 200F for 15 min, then without taking the tarts out, turn the oven to 350°F
Bake another 10-15 min, until they start to brown. This method will prevent them from boiling over.
Note: I use Tender flake lard and make the pastry using the instructions on the box, chilling the dough before rolling. Roll it a little thicker than for pie pastry, and use a little extra flour.
Alternatively you can use frozen tart shells from the grocery.