Cook the pasta until al dente, according to the package directions. Drain, reserving some of the starchy pasta water. (If not adding the peanut sauce right away, it is helpful to toss with a teaspoon or two of canola oil.)
For the peanut dressing: Place the peanut butter, soy sauce, vinegar, sesame and canola oil, garlic, ginger, and honey in a blender or food processor and process until smooth. Thin with the reserved pasta water, 1 tablespoon at a time, until thick but pourable. (You may prepare the sauce a day or two in advance, refrigerate, and thin when cooking the pasta. I add 2-3 tablespoons of the water, leaning toward the larger amount when the sauce has been refrigerated overnight.
For the salad: Place the cooked pasta in a large mixing bowl (or simply use the pot you cooked it in), add the vegetables, and toss with the dressing. I typically add about 3/4 of the dressing immediately and drizzle with the remaining amount when ready to serve.
Top with the chopped peanuts and/or toasted sesame seeds and cilantro, if using, and serve cold or at room temperature.