Preheat the oven to 350 F. Cut the pumpkins in half, scoop out the seeds and place skin-side down on a baking sheet. Bake for 35 to 45 minutes, or until soft. Scoop out the pumpkin flesh into food processor and puree until smooth. Pour pureed pumpkin into a saucepan and add the chicken broth, water, maple syrup and spices. Bring to a boil, then reduce to a simmer and cook for 30 minutes. Remove the soup from heat and stir in the half and half.