From America's Test Kitchen. A recipe designed to render a crispy crust. They say: "Thawing the frozen puff pastry in the refrigerator overnight will help prevent cracking while unfolding it. Be sure to use a low-moisture supermarket mozzarella sold in block form, not fresh water-packed mozzarella. If you prefer to do some advanced preparation, the tart shell can be prebaked through step 1, cooled to room temperature, wrapped in plastic wrap, and kept at room temperature for up to two days before being topped and baked with the mozzarella and tomatoes. "