Making Peanut Butter Cake Frosting Fudge?

I have had success using Allrecipes. It recommends an 18 ounce jar of peanut butter and a container of frosting www.allrecipes.com/.../

I am not exactly clear what you are asking. Are you making peanut butter fudge or peanut butter cake with fudge frosting?

The latter was a staple of my childhood and if that is what you are looking for I will see if I can dig up the family recipe.

If it is fudge, I think I saved a good one for that too.

Please let me know!

Yes you will need a tub of frosting but the amount of peanut butter you add will also depend on you. The reason you see people saying 1 cup and other saying 16 ounces is because they like it to have a more peanut butter taste.