Lay the zucchini on a chopping board. Using the side of a wide knife or a rolling pin, gently smack them until they break apart (be careful, they will want to fly off the board). Tear or cut into bite-sized pieces. Place the smashed zucchini in a colander and sprinkle with a 1 teaspoon of salt. Allow to sit for 15-20 minutes to draw out any excess water. Drain off any liquid and pat dry with paper towel or a clean tea towel.
Meanwhile, bring a large pot of salted water to the boil. Add the noodles and cook according to package instructions until al dente. Drain and then run under water until completely cold. Add the sesame oil, toss well to coat the noodles (to prevent sticking) and place them into the fridge.
In a large bowl (big enough to toss the noodles), add the chili crisp or oil, black vinegar, soy sauce or tamari, sugar, cumin, Sichuan peppercorns (if using), sesame paste or tahini and 1 tablespoon of water and whisk to combine. Taste to make sure you are happy with the flavour - it should be nicely balanced with saltiness and acid with a hint of sweetness - and adjust if needed.
Remove the noodles from the fridge and loosen them by tossing them with your hands. If they have clumped together, run under cold water and then drain. Place the noodles into the bowl with the spicy sauce, and add the zucchini. Toss until well combined. To serve, top with peanuts, coriander/cilantro and more chili crisp/oil, if you like.
Notes
This recipe is best served cold. You can prepare the noodles and sauce ahead and then combine when you are ready to eat.