Microwave the squashes for about 8-10 minutes. Let cool, slice in half and remove the seeds. Preheat the oven to 350 degrees F.
In a large saucepan, sauté garlic in olive oil. Add the chopped sweet potatoes. Sauté for about 10 minutes or until sweet potatoes are tender. Add in the chopped celery, diced apples, salt, pepper, and chicken bouillon.
Combine rice with the vegetable mixture. Add dried cranberries and mix until ingredients are well incorporated.
Stuff the squashes with the vegetable and rice mixture. Cover the stuffed squashes with tin foil. Place the squashes on a large cookie sheet and cook for 45-50 minutes or until tender.
Remove from the oven and top with chopped pecans if desired.