Preheat grill to medium-high heat.
Grill corn for 10–12 minutes, turning occasionally until lightly charred. Allow to cool slightly, then cut kernels from the cob.
Dice avocados and cucumber into bite-sized pieces. Slice tomatoes and finely dice onion and jalapeño if using.
In a small bowl, whisk together olive oil, lime juice, honey, salt, and pepper.
In a large bowl, combine grilled corn, avocado, tomatoes, cucumber, onion, cilantro, and jalapeño.
Pour dressing over salad and toss gently until combined.
Top with feta or cotija cheese if desired and serve immediately.