Ingredients

• 1 1/2 cups all-purpose flour
• 1 large egg
• 1 1/2 teaspoons salt
• 1 tablespoon extra-virgin olive oil
• 1/4 to 1/3 cup water
• 2/3 cup heavy cream
• 4 teaspoons truffle butter
• 1 ounce grated Parmigiano-Reggiano (1/2 cup)
• grated Parmigiano-Reggiano

Instructions

1. Sift flour in a mound on a wooden board or work surface and make a well in center. Add egg, salt, oil, and 1/4 cup water to well and mix with a fork, gathering flour gradually into egg mixture to form a dough. If it seems dry, add water (up to 2 tablespoons). Knead on a lightly floured surface, incorporating just enough flour to keep dough from sticking, until smooth and elastic, 8 to 10 minutes.
2. Quarter dough. Working with 1 piece at a time (keep remainder covered with plastic wrap), roll dough between your palms into a 6-inch log, then cut crosswise into about 26 (1/8-inch-thick) pieces. Roll each piece between your palms into a 3-inch-long log that is 1/4 inch thick in center, tapering to 1/8 inch thick at ends. Transfer to a flour-dusted kitchen towel (not terry cloth).
3. Cook gnocchi in a pasta pot of boiling salted water (2 tablespoons salt for 6 quarts water) until cooked through, 15 to 18 minutes.
4. Meanwhile, heat cream with truffle butter and 1/4 teaspoon each of salt and pepper in a 12-inch heavy skillet over medium heat until hot.
5. Drain pasta and add to cream mixture along with cheese, then toss over medium-high heat until coated.