Start by preheating the oven to 400F and lining a baking sheet with non-stick spray or parchment paper.
In a large bowl stir together the ground beef, onions, egg, salt, pepper, cheese, garlic, and bread crumbs. Mix until well combined.
Scoop into even size balls and line the baking sheet. (About 1- 1 ½ -inch balls). Bake for
Bake for 15-20 minutes. Set aside when done.
While the meatballs are baking, cook pasta according to box directions for aldente, drain and set aside. This takes around 9 minutes.
Over medium heat, in a large, raised edge skillet whisk together the melted butter, pumpkin puree and minced garlic for 60 seconds or until garlic becomes fragrant.
Stir in the cream, cheese, nutmeg, Dijon mustard, salt and pepper. Simmer and stir until cheese has melted and ingredients are married.
To the warm sauce, add the cooked noodles and spinach. Toss until all components are saucy.
Nestle meatballs into the dish and top with fresh herbs or cheese as desired.