DRESSING: In a medium-sized bowl, stir together the Zesty Italian Dressing with the Italian dressing seasoning mix (See Note 1) and whisk until combined. Refrigerate while preparing the rest of the salad.
PASTA: Prepare the pasta according to package directions. Make sure to generously salt the water (I add 1 teaspoon to every 4 cups of water). Don't forget to salt the pasta water or the whole salad will taste underseasoned. Drain, rinse under cold water, and toss with 2 tablespoons of the prepared Italian dressing. Set aside.
CORN: You can cut it straight off the cob and add to the salad raw (more crunchy!) or grill it. To grill the corn, preheat a grill to medium-high heat, around 400 degrees F. Once hot, clean the grill grates. Remove the husks and silk from the corn. Pour about 1 teaspoon of vegetable oil on each corn cob and rub that oil into all the sides. Very lightly sprinkle salt and pepper on all sides of the corn. Place corn on bare grill grates (don't wrap in foil) and close the grill. Allow corn to cook (temps remaining at 400F) for about 3 minutes per side undisturbed. Using tongs, rotate and continue cooking on each side, for about 12 minutes total. When all sides are browned, remove from the grill onto a plate. Let cool and then cut off the cob.
ZUCCHINI: Add the chopped zucchini to a large, preheated skillet. Do not add any oil or butter; try to spread pieces in an even layer. Sprinkle with salt and pepper as desired and allow it to sit, over medium-high heat, without stirring. Let the zucchini roast for a few minutes before stirring. Continue to let it sit and brown in between stirring it until the zucchini is lightly browned and roasted outside. Set aside to a plate to let cool in the fridge.
TOMATOES AND AVOCADO: Halve the cherry tomatoes and thinly slice or chop the avocado. If desired, toss the avocado with the lemon juice to keep it from browning.
ASSEMBLE: Place the cooled pasta in a large bowl. Add the corn, zucchini, tomatoes, and avocado. Stir in the dressing to preference (we add it all!) and toss to combine. Season with salt and pepper if needed; top with fresh basil and Parmesan cheese if desired.
STORAGE: This salad is best enjoyed the same day you've made it.