Cocoa butter is hard to beat, but I've recently become a big fan of Cupuacu Butter, Pretty similar - but oh so nice!
The only reason is becuase I scoured EBAY and some guy has a drum of it and is selling it pretty cheap by the lb relatively speaking. I bought 10 lbs and while folks may not really be able to tell the difference in soap recipe tests - It really blends nicely. Smells different that Cocoa even though they are closely related. If you tell them up front it's in the soap, they think they can tell you the difference....but hand them identical bars with cocoa or cupuacu and they say they are the same :shock:
BTW, I originally formulated this soap recipe with Babassu oil instead of Palm, but too expensive and despite a firmer bar, I didn't think it was worth the cost. It didn't pop out as being significant for Cleansing, conditioning, lather, etc. Sometimes it does, but not with this recipe.