I think you could make carob peanut butter cups just by using a regular chocolate peanut butter cup recipe and exchanging the chocolate for carob. Have you tried that?
Let us know if that works well for you. Does anyone else have a recipe for making peanut butter cups with carob or some personal experience to share?
My mom got me into this one! She made it (with my sisters and I) for Christmas a few years back. I will never forget that day! We had a blast in the kitchen.