My mother makes this snack/dessert when she finds a great pumpkin. Her criteria for picking a pumpkin is that the flesh has to be very dense to the point where it's hard to remove the cutting knife from the pumpkin because there was no air space. In Thailand, a vendor would gladly cut up a wedge of pumpkin to show you how great it is. This pumpkin is gummy not fluffy when cooked. The mouth feel should be creamy and nutty. And when you have such a great pumpkin, it's the star of the show.
The pumpkins here in the US that comes closest to my mother's criteria is kabocha. Added bonus is that you can eat the kabocha skin and the green line of the skin looks so beautiful against the bright yellow flesh