Using gummy, stabilizer-packed supermarket cheese to make a ricotta torta is an exercise in futility. Even with Calabro, the only widely available brand of supermarket ricotta that meets our approval, the pies came out baked unevenly, with an unpleasantly wet and grainy texture.
We wanted a ricotta torta with light texture, mild sweetness, and tender curds of ricotta, plus an even texture from edge to center and a perfect, golden crust.
Regular supermarket ricotta was definitely out. This left us with two options: using Calabro, our only recommended brand, or making our own. We found that Calabro could be used, provided it was carefully blotted with paper towels beforehand to remove excess moisture (which gave the pie a wet curd and weepy texture), but homemade ricotta proved to be as simple as heating milk and adding lemon juice to help it curdle.
Homemade ricotta in hand, we moved on to attaining an even texture. The secret was temperature. If the pie filling was too cold, the torta came out too loose; too high a temperature and the eggs scrambled, resulting in a rubbery texture and water weeping out of the pie. The problem was that by the time the center of the pie reached the optimal temperature, the outer edges were too hot. Cooking the pie in a 200-degree oven helped but took more than 3 hours and produced a pie with a dried-out top and no browning.
The answer to our problems came when we combined two temperature extremes. By cranking the oven up and placing the pie in a roasting pan filled with an ice-water bath, we gave the pie a quick browning while keeping the outer edges from overcooking. We then reduced the temperature to let the pie cook through gently and, more importantly, evenly.