Microwave butter and peanut butter on high for 2 min. stir and microwave for two more minutes. add vanilla and powdered sugar to the peanut butter mixture and stir with a wooden spoon.
quickley pour into a buttered 8x8 pan lined with wax paper. place a 2nd piece of waxed paper on the surface of the fudge and refrigerate until cool. cut into 1-inch pieces and store in a airtight container for up to a week.