Cook noodles according to package instructions then rinse in cold water to cool them quickly and stop them from sticking together. Set aside to drain.
Meanwhile, whisk together all the sesame dressing ingredients in a large mixing bowl. Set aside.
Cut the cucumber in half lengthwise, then remove the seedy middle with a spoon. Cut into 2-3-inch (5-8 cm) matchsticks approximately the same width as cooked noodles.
Add the drained noodles and 3/4 of the sliced cucumbers to the dressing bowl and stir well to combine. Optionally, transfer to a serving platter.
Top with the remaining cucumber, green onions, cilantro, and chopped peanuts. Garnish with extra lime wedges (optional). Enjoy right away or chill for 30 minutes before serving.
Notes
*If soy-free, use coconut aminos in place of soy sauce/tamari and start with less maple syrup as coconut aminos are naturally sweet.