Bring a large pot of salted water to a boil. Add the jumbo pasta shells and cook for 8-10 minutes until al dente. Drain and drizzle with olive oil.

In a food processor, combine tofu, nutritional yeast, garlic powder, onion powder, salt, pepper, olive oil, lemon zest, and juice until chunky-smooth.

In a bowl, fold together tofu ricotta, pumpkin puree, nutmeg, and parmesan until well mixed.

In a saucepan, heat olive oil and sauté chopped onions until softened. Add garlic, then whisk in flour and gradually pour in coconut milk, stirring until thickened.

Preheat oven to 350°F. Spread béchamel sauce in a baking dish, fill shells with pumpkin mixture, place them in the dish, and pour remaining sauce over top.

Bake for 22-25 minutes until bubbly and golden brown. Allow to cool slightly before serving.