Step 2. Add the tamari, nutritional yeast, chili powder, smoked paprika, chipotle, garlic powder, and olive oil in a small bowl. Use your hands to rub the marinade on the crumbles until they are evenly coated.
Step 3. Spread the crumbles in an even layer on the baking sheet. Bake for 15 minutes. Remove from the oven and toss the crumbles. Return to the oven and cook for about 10 minutes, or until the crumbles are browned. Change the oven setting to broil and cook for about 2 minutes more, or until the crumbles are crispy.
Step 6. Stir to combine. Then simmer for 5 minutes. Mix in the desired amount of cooked spaghetti (if using) and continue cooking until warmed through. Season with salt and pepper. Garnish with basil.