Remove stem and blossom ends of squash and cut them into large chunks. Place in a large saucepan and cover with water.
Bring to a boil over medium-high heat. Reduce the heat to low, cover the pan, and cook until squash is very tender about 10 to 15 minutes. Drain thoroughly.
In a large bowl, mash the drained squash. Add the remaining ingredients to the mashed squash and blend well.