Preheat the oven to 375˚F.
Beat together the sugar and egg. In a separate bowl, combine the flour and baking powder.
Alternate between mixing in the milk and flour mixture and beat in after each addition.
Mix in the vanilla and the butter.
Bake for 5 minutes, then remove from oven temporarily to plop a caramel kiss inside each muffin, then return to oven to bake for another 10-15 minutes. Remove from oven and let cool on wire racks.