In a pan mix the 2 sugars, the butter & miik. Bring to a boil, then turn down to a steady rolling boil. Keep cooking it until it reaches 185 degrees (Soft Ball) on a candy thermometer or when a drop of mixture turns to a soft ball when dropped in water.
When this is reached, take off stove and stir in the vanilla and the peanut butter. Mix well and pour and spread out on a butter sheet or plate. Let set up....then cut and enjoy.