Cook spaghetti in boiling water until al dente, then drain and toss with olive oil, salt, and pepper. Pop it into the fridge to cool while you move on to the next steps.
Transfer the cooled spaghetti to a large bowl, then add red pepper, cabbage, carrots, edamame, and green onion. This sets up a colorful, crunchy base for your salad.
Pour soy sauce, rice vinegar, olive oil, tahini, sesame oil, brown sugar, ground ginger, and garlic powder into a mason jar. Seal the lid so nothing leaks out when you shake.
Hold the jar firmly and shake until the mixture turns smooth and creamy and the brown sugar disappears. You’ll see it coat the jar walls evenly.
Open the jar and pour the sesame ginger dressing over the pasta and veggies, aiming for the edges so every strand gets a bit of sauce.
Use tongs or two forks to gently toss the salad, ensuring the dressing clings to each noodle and vegetable without crushing them.
Sprinkle sesame seeds over the top, give the salad one last gentle toss, and serve it chilled so the flavors stay bright and the seeds stick.