Whisk together all of the ingredients for the stir fry sauce and set aside.
Cook the Noodles
Bring a pot of boiled water to a boil. Add the noodles and cook according to package directions, then tDrain and rinse with cold water. Set aside.
Make the Tofu
Heat a large skillet over medium heat. Add the teaspoon of oil, then crumble in the tofu and cook until very dry, chewy and golden brown, stirring often. This will take about 8-10 minutes.
Add 2 tablespoons of the reserved stir-fry sauce and cook for another minute or two, until the tofu is well coated and sauce has thickened around the tofu. Remove from the skillet and set aside.
Combine
Add the remaining sauce to the empty sauce pan and cook for 3-4 minutes, stirring often to prevent burning, until the sauce is bubbly and thickened.
Add in the cooked noodles, tofu and spinach. Toss, cooking another minute or two until the spiinahas wilted and everything is warmed through. If the sauce becomes too thick, add a tablespoon or two of water.
Divide between two bowls (this makes two large servings, but so good and my husband and I easily eat it as a serving!) and garnish with sesame seeds and scallions, if desired.