Start by boiling water for the pasta and cooking it until el dente.
While the pasta is cooking, melt the butter in a large skillet. Cook the corn, stirring often, until it's lightly charred. Transfer to a salad bowl.
Chop the scallions, jalapeno, fresh cilantro, and avocado (if using)
Drain the pasta and cool with cold water. Toss the pasta with oil while you finish preparing the salad components so it doesn't stick together.
Whisk together the dressing ingredients.
When ready to serve, toss the charred corn with cooled pasta, scallions, jalapeno, fresh cilantro and avocado. Sprinkle in the parmesan and drizzle on the dressing.
Mix well and serve immediately.