Prepare a large piece of tin foil. Place salmon portions onto the foil, skin side down. Pat salmon dry with a paper towel. Combine cumin, light brown sugar, garlic powder and salt in a small bowl. Coat salmon on top and sides with spice rub. Set aside, at room temperature for 30 minutes while you make the corn salad.
Meanwhile, heat a large pot filled halfway with water over high heat until boiling. Add corn, cover, bring back to a boil, then lightly boil for 5 minutes. Remove corn from pot with tongs and let cool slightly. Once corn is cool enough to handle, slice the corn off the cobs into a large serving bowl.
Add tomatoes, mozzarella, red onion, white wine vinegar, extra virgin olive oil, salt and pepper to the bowl with the corn. Toss to combine. Add in basil and toss again gently. Set aside.
Preheat grill to high heat. Clean grates. Place salmon (keeping it on the foil) onto grill and reduce heat to medium high. Grill until salmon flakes easily with a fork and until it’s just barely opaque in the thickest part of the filet (time will vary depending on the thickness of your filets, but a good rule of thumb is to cook the fish 8-10 minutes per inch of thickness). You do not need to flip the salmon. Remove salmon from the grill. Using tongs, place filets overtop corn salad.
Serve with lime wedges, your favorite loaf of bread and softened butter.