Wow this one is atis here, they have similarities with guyabano or soursop in terms of what is inside, white food and the black seeds but this one is sweet. I remember my father planted this fruit before but that lot was being sold so it is not ours right now. I haven't tried to make a smoothie out of it too but for sure it won't need condensed milk because it is already sweet.
Thanks for visiting and reading my post @livinguktaiwan.