The Dutch process version had an earthier but flatter flavor; the natural cocoa version was fruitier, but also more acidic. (seriouseats.com)
This is another recipe where carob powder could also be used in place of, or mixed in with the cocoa for extra depth and sweetness and a twist on the usual taste... I tentitively tried the carob version recently and I was very pleasantly surprised, it tatsed really good and not so dissimilar the the original cocoa version. (includingcake.com)
I have been looking into Weston A Price and cacao is mentioned as being high in phytic acid - do you know how much and if the roasted cocoa version is lower? (bodyunburdened.com)