Cook pasta shells in salted boiling water until al dente, then drain and set aside.
Heat olive oil in a skillet over medium heat and sauté garlic for 1 minute.
Add spinach and cook until wilted, about 2 minutes.
In a mixing bowl, combine crumbled tofu, sautéed spinach, nutritional yeast, Italian seasoning, salt, and black pepper.
Stir in dairy-free ricotta for extra creaminess (optional).
Spread 1 cup of marinara sauce in the bottom of a baking dish.
Stuff each shell with the tofu-spinach mixture and arrange in the dish.
Pour the remaining marinara sauce over the shells.
Sprinkle with red pepper flakes and fresh basil.
Bake at 375°F (190°C) for 25 minutes until bubbly and slightly crispy.
