I use cupuassu pulp (haven't actually had it for several years but I used to get it once a year) in about the same ratio as cacao powder (though the flavor is very different), a little more cupuassu pulp than cacao though.
1 large glass of milk
~2tbs cupuassu pulp
sugar to taste (2-4tbs)
cupuassu pulp should be blended before hand, grind with the sugar, slowly add milk.
drink and relax!