Bring a pot of water to a boil and cook the soba noodles for 5-6 minutes until tender, then drain and rinse with cold water.
Press the firm tofu to remove excess moisture, then cut it into 1-inch cubes.
In a small bowl, whisk together the peanut butter, nutritional yeast, tamari, lime juice, sriracha, garlic powder, ground ginger, and water until smooth.
Heat the sesame oil in a large non-stick skillet over medium-high heat and add the tofu cubes, searing until golden brown on all sides.
Add the sliced red bell pepper and shelled edamame to the skillet, sautéing for 3-4 minutes until the pepper is slightly softened.
Stir in the fresh spinach and cooked soba noodles, tossing gently until the spinach begins to wilt.
Pour the peanut satay sauce over the mixture and stir well to coat everything evenly before serving warm.