In a medium saucepan melt butter, brown sugar, and corn syrup and stir.
Bring mixture to a boil and stir in milk.
Continue stirring until a thermometer reads 248 degrees.
Remove from heat and stir in vanilla. Set aside.
Meanwhile, insert sticks into the apple slices.
Dip into the caramel and place on baking sheet with greased wax paper.
Top with sprinkles, if desired.
Refrigerate for 1 hour.