Toss the bread cubes with ½ tbsp of oil, ground black pepper and salt.
Heat a wok or large saucepan and add the bread cubes. Stir-fry the cubes until they start to turn golden-brown and crunchy. Remove to a plate and set aside.
To the same pan, add the remaining oil. Add the garlic and the vegan sausage. Cook, stirring frequently, until the sausage starts to brown a little and is in separate bits, not clumped together. Help it if needed by pressing down with the tip of a spatula and separating it as it cooks.
Add the spinach along with the nutmeg and the oregano. Cook, tossing, until the spinach wilts, about 2-3 minutes. Add salt and ground black pepper to taste and turn off heat.
Place the tofu in a blender along with the milk, garlic powder, onion powder, pepper and salt and blend into a smooth paste.
Lightly oil a 2-quart baking dish, or coat lightly with cooking spray. Layer half the bread cubes evenly at the bottom of the casserole.
Layer on the spinach-sausage mixture and then sprinkle on half the cheese.
Layer on the remaining bread cubes and sprinkle on the remaining cheese.
Pour the tofu cream evenly over the bread cubes, pressing down with a spoon or ladle if needed to ensure the bread cubes are immersed. Some will still peek from the top but that's okay--you just want to make sure they absorb some of the moisture.
At this stage you can either walk away for 15 minutes and bake to serve rightaway. Or cover with cling wrap and place in the refrigerator overnight. You can also freeze this casserole for several days and thaw before baking.
Preheat the oven to 350 degrees Fahrenheit. Place the casserole inside the oven (don't forget to remove the cling wrap if you used it) and bake 50 minutes or until bubbly and the bread cubes are nice and golden.
Let stand at least 10 minutes before serving.