caramel apple recipe

Ingredients: 6 small apples (Granny Smith or Honeycrisp work well) 6 wooden sticks 1 cup unsalted butter 2 cups packed brown sugar 1 cup light corn syrup 1 can (14 ounces) sweetened condensed milk 1 teaspoon vanilla extract Optional toppings: chopped nuts, sprinkles, mini chocolate chips, crushed cookies