Bring a large pot of salted water to a boil over high heat. Add pasta and cook according to package instructions for 7-10 minutes. Reserve a cup of pasta water, drain, and set aside.

Preheat oven to 350°F (175°C). Spread pine nuts on a baking sheet and toast for 7-10 minutes until golden brown.

In a large skillet, heat olive oil over medium heat. Sauté diced onion for 7-10 minutes until translucent. Add minced garlic and cook for an additional 30 seconds until fragrant.

Reduce heat to low, stir in sage, vegetable broth, pumpkin puree, and plant-based milk. Simmer for 7 minutes, stirring occasionally. Season with salt and pepper to taste.

Add drained pasta to the skillet and toss to coat with the sauce. If too thick, incorporate reserved pasta water gradually.

Serve the pasta in bowls topped with toasted pine nuts and additional sage leaves if desired.