Preheat the oven to 400 degrees.

Core the apples, maintaining the peel, and place on a sheet pan. Roast in the oven 20 minutes, until soft and juicy. Remove and allow to cool. Squeeze flesh from peel and discard peel.

In a large bowl, combine the apple flesh with the ricotta, egg, amaretti, 1/4 cup cheese and salt and mix well to combine.

Roll out the pasta to the thinnest setting on a pasta rolling machine, then cut into 2-inch squares. In center of half of the squares, place a scant tablespoon full of the apple and cheese mixture. Moisten the edges of these squares with water, then top each square with an un-filled square, and press with your fingers to seal the edges.

Bring 6 quarts of water to a boil and add 2 tablespoons salt.

In a 12-to 14-inch sauté pan, heat the butter until it foams and subsides.

Meanwhile, drop the pasta in the boiling water and cook 3 minutes. Drain the pasta, reserving the cooking liquid, and add the pasta to the pan with the butter. Add a splash of the pasta water if necessary to keep the sauce from becoming too "tight." Toss over high heat 1 minute to coat.

Divide pasta evenly among 6 warmed pasta bowls, top with grated Parmigiano-Reggiano, and serve immediately.

This recipe yields 6 servings.