In the bowl of an electric mixer, blend together cream cheese, peanut butter, vanilla and powdered sugar until fluffy and creamy. Spread mixture on a NILLA Wafer, then sandwich with another NILLA Wafer. Repeat until mixture is gone. Dip each sandwich cookie halfway into the melted chocolate and immediately add sprinkles. Allow the chocolate to set completely. These are best when fresh, so make them just before you're ready to serve!