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 pumpkin purée, milk, vinegar, vegetable broth, salt, and pepper.
Quickly whisk and simmer for about 4-5 minutes.
Whisk in the sage and parmesan.
Turn off the heat and continue to whisk for 2-3 minutes, until sauce thickens slightly.
Stir in spinach, then add in the cooked pasta.
Top with walnuts, pepitas, extra parmesan if desired, and garnish with sage.
Enjoy!