For the tofu and mushrooms: Put the tofu slices in a dish or plastic bag and pour over the soy sauce. Turn the tofu pieces to coat evenly in the soy sauce, but no need to let marinate. Heat the oil in a large skillet or non-stick frying pan over medium heat. When hot add the tofu slices. Slowly fry the tofu until very golden and crispy, then flip and repeat on the other side. Remove the crispy tofu slices from the pan and set aside.
Return the pan to the heat and add the mushrooms. Slowly sauté the mushrooms, stirring as needed until reduced in size and golden brown. When finished cooking, pour over any remaining soy sauce from the tofu and stir to coat. Remove from the heat.
To make the vegan ramen noodle soup: Heat the oil in a soup pot over medium-high heat. Add the garlic and ginger and sauté, stirring for about a minute until the garlic just starts to brown. Pour in the vegetable broth and bring to a boil. When boiling, add the noodles and cook until they are al dente. Just before serving, stir the spinach into the soup so it wilts. To serve: Divide the soup among bowls, top with tofu, mushrooms, grated carrots, and any additional toppings you desire.