In a food processor, combine tofu, lemon juice, garlic, salt, pepper, and parsley. Puree until smooth. Transfer mixture into a bowl. Add olive oil and nutritional yeast. Refrigerate until ready to stuff shells.
Preheat oven to 350 degrees. In a large roasting pan, combine squash, onion, garlic, herbs, brown sugar, salt and pepper. Drizzle with the olive oil and stir, making sure everything is coated with oil. Place ice cubes on top of the mixture. Cover with foil, and bake for 30-35 minutes or until squash is soft.
Remove foil and allow the mixture to cool until it can be handled. Once cooled, pour mixture into a food processor and puree until smooth.
Cook the shells according to the package directions. Drain and rinse with cold water.
In a 13x9” baking pan, add a thin layer of pasta sauce (Francesco Rinaldi Sweet and Tasty Tomato is the best, but you can use any type you’d like!) Stuff each shell half-way with the squash mixture and top with the tofu ricotta. Once all of the shells have been stuffed, top with the remaining pasta sauce. Bake at 350 for 25-30 minutes