Preheat oven to 375°F.
Mix together tofu, nutritional yeast, garlic, lemon juice, basil, parsley, onion powder, salt, black pepper, and cayenne pepper a food processer until smooth and creamy.
Add the artichoke hearts and spinach, and pulse until thoroughly incorporated.
Pour the mixture into a small casserole dish, and smooth the top with a spatula or wooden spoon.
Bake for 15-20 minutes, or until lightly browned on top.
Serve warm with crackers, bread, or cut vegetables.