Spray slow cooker with non-stick cooking spray.
In a large sauté pan, heat olive oil over medium heat then sauté onions for about 2 minutes.
Add the ground turkey to the onions in the pan.
Add the sage, basil, cinnamon, cayenne pepper, salt and pepper to the pan. Break up the turkey and brown for about 8 minutes, or until no longer pink.
Add the minced garlic and tomato paste and cook for an additional 2 minutes. Then use 1/2 cup of chicken broth to deglaze the pan.
Remove pan from heat and spoon all contents of pan into the slow cooker.
Add the crushed tomatoes and chicken broth to the slow cooker. Cover and cook on low for 5 - 6 hours. Stir occasionally.
After the sauce has been cooking for about 4 - 5 hours, prepare and put the squash in the oven.
Once the squash is in the oven, add the 2 tablespoons of butter to the slow cooker and stir until melted. Recover until the squash is ready to be served.