Make the cheese. Crumble the tofu in and mix with the cheese. Add the spinach and whatever spices you need. Place a thin layer of tomato sauce on the bottom of a 9 x 12 inch (23 x 30 centimeter) casserole pan and stuff manicotti with the cheese mixture. Place them on top of the tomato layer. Cover with remaining sauce. Cover with foil and bake at 180C/350F for 30-40 minutes.