Melt butter in a medium saucepan over medium heat. Stir in brown sugar and evaporated milk. Bring to a boil and boil for 2 minutes, stirring frequently.
Remove from heat. Stir in peanut butter and vanilla.
Pour over confectioners' sugar in a large mixing bowl.
7. Cut in to 1-inch squares, clean knife between cuts for best results. Keep in refrigerator.
Perfect for the holidays, enjoy!