8 small (or 4 large) ripe peaches, sliced 1/2"-thick
1/2 c. torn fresh basil leaves, plus more for serving
1 8-oz. ball burrata
Preheat oven to 425°. Combine red onion and balsamic vinegar in a small bowl and set aside.
On a baking sheet, toss bread cubes in 1 tablespoon olive oil and season with salt. Bake until crisp but not brown, 5 minutes, then let cool.
Gently toss peaches with 1 tablespoon olive oil and season with salt and pepper. Heat grill or grill pan over medium-high heat. Working in batches, grill peaches until slightly charred, 2 to 3 minutes, then flip and grill 2 minutes more. Transfer to a large baking sheet to cool.
Pour ¼ cup balsamic vinegar from marinated onions into a large bowl and whisk in 6 tablespoons olive oil, then season with salt and pepper.
Strain onions, discarding remaining vinegar, and add onions, bread cubes, peaches, and basil to large bowl. Gently toss with vinaigrette.
Divide panzanella onto 4 plates and top each with burrata. Garnish with basil and a drizzle of olive oil.