Drain the water out of the tofu. Wrap it in a towel or paper towel and press the excess water out of it.
Add drained tofu, margarine, nutritional yeast, vegan cheese, and some salt and pepper to the food processor and blend.
Slowly add the soy milk until it turns to a smooth batter like consistency. (The amount needed will depend on the moisture in your tofu).
In a frying pan, saute the onions in the oil on low for about 5 minutes.
Add mushrooms to the onions then sprinkle with salt and sauté on medium low until mushrooms are cooked.
Add baby spinach and cook for another minute or two until it wilts.
Add the vegetables and cheese to the food processor and pulse a few more times until blended thoroughly.
Use spray oil or a little vegetable oil to grease the muffin tins.
Fill each muffin to the top of the tin. (They will not rise).
Add a spiral of zucchini, yellow squash, or Chinese eggplant to the center of each muffin if desired by cutting the squash into long very thin slices and rolling it up to look like a flower bud.
Bake at 400°F (200°C) 25 minutes.
Let cool a little before taking out of muffin tins.
Notes
Use 1/4 cup of soy milk if using high protein tofu. Reduce the milk a little if using regular tofu since it will be wetter.
The batter should be a thick ricotta cheese type consistency.
Serve warm or cold.
These work great as make-ahead breakfasts or grab and go snacks.