Glykia kolokythopita or sweet squash pie is an autumn and winter sweet which is not too sweet and is healthy too. I reckon you could leave out the oil and halve the sugar without making much of a difference.
Grating a kilo of squash is a tiresome affair but it gets done if you've got your mind on the finished 'pie'.
You can use a short pastry or even a puff pastry. I used filo (phyllo) and my layers were too thin. It needs a thicker pastry which is why I am making a second tray a few days later using handmade pastry. I shall not mention that the first dish of these pies has already disappeared.