Make the croutons: Preheat your oven to 400°F. In a large bowl, toss the cubed bread with olive oil, salt, pepper, and garlic powder until evenly coated. Spread onto a baking sheet and bake for about 10 minutes or until golden and crisp.
In a small bowl, combine olive oil, lemon juice and zest, grated garlic, salt, pepper, parsley and Dijon mustard. Whisk until fully emulsified. Taste and adjust seasoning as needed.
In a large serving bowl, add the cherry tomatoes, cucumber, red onion, bell peppers, nectarines, and toasted croutons. Pour the dressing over everything and gently toss until combined.
Tear the burrata into pieces and scatter over the top of the salad. Finish with a little more salt and fresh cracked pepper, if desired. Serve immediately.