Combine meat, pumpkin, onion, garlic, salt, pepper, parsley, and parmesan (if using) together in a large bowl. Mix gently with your fingers to combine.
Form meatballs about 1 1/2 inches in diameter (I get about 15 total), and place onto a parchment paper-lined baking sheet.
Bake for 12-14 minutes or until internal temperature is 165 degrees F.
Notes
Nutrition facts based on using 85% ground beef and NO parmesan.Weight Watchers points: 2