Bring a large saucepan of water to a boil over medium-high heat. Meanwhile, make the garlic-scallion and tahini sauces.
Mince 1 large or 2 small garlic cloves. Thinly slice 1 medium scallion. Place the garlic and the scallion white and light green parts in a heatproof bowl that holds at least 1 cup; reserve the dark green parts of the scallion for garnish.
Add 1 teaspoon red pepper flakes, 1 teaspoon toasted sesame seeds, 1 teaspoon garlic powder, 1 teaspoon granulated sugar, and 1/2 teaspoon kosher salt to the bowl with the garlic and scallions.
Place 2 tablespoons tahini, 1 tablespoon white miso paste, 2 teaspoons toasted sesame oil, and 1 tablespoon water in a medium bowl and whisk until combined.
Heat 2 tablespoons neutral oil in a small saucepan or frying pan over high heat until just starting to smoke, about 1 minute. Carefully pour over the garlic mixture (it will sizzle). Stir to combine. Add 1 teaspoon black vinegar and 1 teaspoon soy sauce and stir to combine.
Add 6 ounces dried wheat noodles to the boiling water and cook according to package directions until tender. Turn off the heat. Using chopsticks or tongs, transfer the noodles directly to the bowl with the tahini sauce.
Pour the garlic-scallion oil over the hot noodles. Toss until the noodles are evenly coated with the sauce. If the sauce is too thick, toss in a little bit of noodle cooking water to loosen. Garnish with the reserved scallions, chili crisp, and more sesame seeds.