Stir tomatoes, balsamic vinegar, extra virgin olive oil, basil, cayenne pepper, salt, and black pepper together in a bowl. Let sit until flavors blend, at least 30 minutes.
2
Preheat an outdoor grill for medium-high heat and lightly oil the grate. Brush bread slices with olive oil.
3
Cook bread slices on the preheated grill until browned and crispy, 2 to 3 minutes per side.