Cook the pasta according to directions.
Meanwhile, sauté the olive oil and garlic in a pan for 2-3 minutes over medium-high heat.
Lower the heat to medium, then add in the pumpkin, milk, vinegar, broth, salt, and pepper.
Quickly whisk and simmer for about 4-5 min.
Whisk in the sage and parmesan.
Turn off the heat and continue to whisk for 2-3 minutes, or until the sauce thickens just a bit.
Stir in the spinach, then add in the cooked pasta.
Top with walnuts, pepitas, extra parmesan (optional), and garnish with sage.
