In a medium bowl, whisk together soy sauce, rice vinegar, honey, garlic, sesame oil, red pepper flakes, and cornstarch. Add scallops to the bowl and marinate for at least 10 minutes. Remove scallops but reserve marinade.
Meanwhile, using a spiral vegetable cutter, make spaghetti-like noodles with the zucchini. Pat the noodles dry with paper towels to remove the moisture.
Heat a cast iron pan or heavy sauté pan on medium-high heat and add oil. Sprinkle scallops with salt and pepper. Sear scallops on one side 3 to 4 minutes until golden brown. Flip and sear on other side for about 2 minutes more. Add half of the marinade to the pan to coat the scallops. Remove scallops to a dish and keep warm.
Add the zucchini noodles to the pan and cook quickly until the sauce coats the zucchini noodles. It should be al dente. Serve immediately with the scallops on the side or on top of the zucchini.
Garnish with chopped cilantro and sesame seeds.
