Kick the tires and light the fires and pre-heat your oven to 375 degrees
Melt your butter then add in the vanilla,egg, cream and brown sugar.
Mix in the raisins.
Put your tart shells, still frozen, on the tray and fill a good ¾ of the way. I say still frozen because I have found when they are defrosted the filling leaks through the pasty, not ruining them, but making them softer. A good frozen tart shell will hold the contents in, and cook at the same time.
Bake in a 375 degree oven for 15-20 minutes, until the rims of the tarts are beautifully browned and the filling is bubbling.