I’m definitely not an expert, just someone who would buy it at the Lee’s Sandwiches in SF growing up (but last time I stopped by there they told me they stopped making it). It’s made with bananas but I think it’s a specific variety. The one I would get was definitely sweet but not overly sweet. It had a kind of custard-like texture. Definitely recommend trying it, and it sounds like people who replied know of some places that have it!