1. Place the boneless, skinless chicken breasts or thighs at the bottom of your slow cooker. You can leave them whole or cut them into larger pieces if you prefer.

2. In a medium bowl, combine the pumpkin puree, cottage cheese, softened cream cheese, and chicken broth. Whisk these ingredients together until the mixture is relatively smooth.

3. Add the garlic powder, onion powder, dried sage, salt, and black pepper to the pumpkin mixture. Stir well to ensure all the seasonings are evenly distributed throughout the sauce.

4. Pour the seasoned pumpkin and cheese mixture over the chicken in the slow cooker, making sure the chicken is mostly submerged in the sauce.

5. Cover the slow cooker with its lid. Cook on the LOW setting for 6-8 hours, or on the HIGH setting for 3-4 hours. The chicken is done when it shreds easily with two forks.

6. Once the chicken is cooked through and tender, carefully remove it from the slow cooker. Shred the chicken using two forks, then return the shredded chicken to the slow cooker and stir it into the creamy pumpkin sauce.

7. While the chicken is being shredded, cook your fettuccine or preferred pasta according to the package directions. Drain the pasta thoroughly.

8. Add the cooked pasta directly to the slow cooker and toss gently to coat it evenly with the creamy pumpkin chicken alfredo sauce. Alternatively, serve the sauce and chicken over individual portions of pasta. Garnish with fresh chopped parsley and a sprinkle of grated Parmesan cheese, if desired.