Preheat the grill to medium-high heat. Place each ear of corn on a large piece of aluminum foil. Put ½ tablespoon of butter on top of each, then roll and seal in the foil. When the grill is hot, add wrapped corn and grill about 5 minutes per side, for a total of 15 minutes. Set aside and cool for 10 minutes. (If you don’t have access to fresh ears of corn, you can use frozen, but thawed, corn and sauté corn in the butter on the stove top for about 5-8 minutes before combining with the remaining ingredients.)
When the corn is cool enough to handle, slice kernels off and place in a large bowl. Add scallions, tomatoes, ricotta salata, and olive oil. Toss to combine. Add salt, to taste.
If using, add basil leaves and give one final toss. Serve warm or at room temperature.