Great Grandma's Butter Tarts

Why I Love This Recipe
Best butter tarts on earth. I swear! (Although no one can seem to make them as well as my great grandma, no matter how hard they try...)
Ingredients You'll Need
1 cup brown sugar
1 egg, well beaten
1 tbsp butter
1 tsp vanilla
1 cup seedless raisins
tart shells
Directions
Mix & beat above ingredients well (minus the shells).
Fill unbaked tart shells 2/3 full.
Bake for 8 mins at 450F, lower temperature to 350F and bake for another 15-20 mins.