To prepare the vinaigrette, place the olive oil, lemon juice, honey, salt and pepper in a blender or jar with a tight fitting lid. Blend or shake vigorously until combined.
In a large bowl, gently toss together the bread, tomatoes, cucumber, mozzarella and basil.
Toss approximately 3/4 of the vinaigrette with the salad ingredients and allow everything to sit for 30 minutes so that the flavors can mingle. If desired, drizzle on the remaining vinaigrette just before serving.
Notes
Heirloom tomatoes can vary quite a bit in size. Aim for approximately 5-6 cups of diced tomatoes in the salad, but you can eye it out. Personally, I prefer more tomatoes than bread.Stale bread is typically used in panzanella salads because it is dry and will hold its shape when the liquid is absorbed. If using fresh bread, you can dry it out by lightly toasting it. Preheat the oven to 350 degrees F. Spread the bread in a single layer on a sheet pan. Toast until lightly crisp and golden on the outside but still tender on the inside, approximately 5-10 minutes, stirring once or twice to toast the bread evenly. Remove from the oven and allow to cool.