the author mentions kobocha squash but does not list how much should be used in the ingredient list? Can you help with that?

Kabocha squashes come in many sizes..you might want to get one on the small size. You could probably substitute another winter squash like butternut, but Kabocha is uniquely "meaty" . It is however, often hard to find.

You can find the complete recipe on her blog (http://thecrunchycarrot.com/2011/10/07/when-life-hands-you-squash/), it calls for: 4 cups 1-inch peeled pieces kabocha squash (about 1 ½ lbs)

The ingredient list show:

3 cups 1 inch peeled pieces of pumpkin (1lb)

So you essentially need 1lb of kabocha.