Bring a large pot of water to boil. Add salt and corn. Cook for 5 minutes, then transfer cobs to a paper towel-lined plate to cool and dry.
When cool, cut the kernels off the cob and transfer the kernels to a medium bowl. Stir in tomatoes. Refrigerate while making the dressing.
DRESSING
In a small saucepan, combine the olive oil, balsamic vinegar, sugar, cornstarch, oregano and basil. Bring to a boil, then reduce the heat and simmer until the dressing thickens slightly, 2 to 3 minutes.
Remove from heat, season with salt and pepper, and set aside to cool.
When ready to serve, drizzle dressing on top of the salad and toss gently. Garnish with additional basil, if desired.