Pennette with cream and lemon

Bring to the boil a large pan with plenty of boiling salted water. Then rinse the lemons and grate the zest (discard the white bitter part) into a bowl, add the single cream and the butter melted at room temperature, fold in all the ingredients with a wooden spoon until a smoothly blended cream is obtained.Cook the pasta and drain al dente, mix with the sauce, generously sprinkle with parmesan and mix well. Arrange the pennette thus seasoned in a serving dish and serve warm.