Whisk eggs and yolks in a bowl. Using a ladle, press the eggs and yolks through a fine-mesh sieve into a bowl; set aside. Bring sugar, lemon zest, and 1 cup water to a boil in a 12" skillet; cook, without stirring, until sugar is dissolved and a candy thermometer inserted in the syrup reads 225°, about 5 minutes. Using a slotted spoon, discard lemon zest; reduce heat to medium. While stirring, slowly drizzle egg mixture into syrup. Cook until small curds form and mixture is very thick and appears slightly curdled, about 15 minutes. Transfer to a 9" pie plate and sprinkle with cinnamon. Guide the flame of a blowtorch back and forth over the top of the egg sweet until the surface caramelizes. (Alternatively, place under oven broiler.) Serve warm or at room temperature.