Subsituting mango puree for bananas in banana bread
Mango puree is quite a bit more acidic than banana; 3.4 to 4.6. vs about 6.5.
Quite a bit more liquid too.
I'd cut to about two bananas worth volume wise, and be quick about stirring in the puree and getting it into your oven. The low pH is liable to set off your rising agent quickly. Take it too slow, and you'll have bread overfilling the pan, or flatbread.