Add balsamic vinegar to a small saucepan over medium-high heat. Bring it to a boil, then reduce the heat to medium-low. Stir occasionally until the vinegar is reduced by half and thick enough to coat the back of a spoon, about 10-15 minutes.

Remove from heat and stir in the honey. Allow the balsamic reduction to cool completely.

If using fresh corn, bring a large pot of water to a boil. Add the corn and cook for 3-5 minutes. Drain and let it cool, then cut the kernels off the cobs.

In a large mixing bowl, combine the corn, mozzarella, cherry tomatoes, avocado, red onion, basil, olive oil, kosher salt, and black pepper. Toss gently to evenly distribute the ingredients.

Drizzle the cooled balsamic reduction over the salad. Toss lightly to coat.

Serve immediately.