Squash And Prosciutto Ravioli Or Tortellini

This recipe produces 2-inch square ravioli or large tortellini.

1. FOR THE FILLING: Adjust oven rack to middle position and heat oven to 400 degrees. Place squash, cut sides down, on rimmed baking sheet and bake until tender, about 35 minutes.
2. Let squash cool slightly, then scoop out flesh and transfer to food processor. Process until squash is smooth, about 20 seconds, scraping down bowl as needed. Transfer squash to large bowl and stir in prosciutto, Parmesan, egg yolk, sage, and nutmeg. Cover and refrigerate mixture until cool, about 30 minutes. (Filling can be refrigerated for up to 2 days.)
   3A. TO FORM RAVIOLI: Dust 2 rimmed baking sheets and counter with flour. Working with 1 pasta sheet at a time, cut pasta into long rectangles measuring 4 inches across with pizza wheel or sharp knife. Place rounded 1-teaspoon dollops of filling 1 inch from bottom edge of dough and spaced about 1-1⁄4 inches apart. (If edges of dough seem dry, dab with water.) Fold top of pasta over filling and press layers of dough together securely around each mound of filling to seal. Using fluted pastry wheel, cut ravioli apart and trim edges. Transfer finished ravioli to prepared sheets and cover with damp kitchen towels. Repeat with remaining pasta and filling. (Towel-covered sheets of ravioli can be wrapped with plastic wrap and refrigerated for up to 4 hours, or frozen; when completely frozen, ravioli can be transferred to zipper-lock bag and stored in freezer for up to 1 month. Do not thaw ravioli before boiling.)
   3B. TO FORM TORTELLINI: Dust 2 rimmed baking sheets and counter with flour. Working with 1 pasta sheet at a time, cut pasta into 2-1⁄2-inch squares with pizza wheel or sharp knife. Place 1⁄2-teaspoon dollops of filling in center of each square. (If edges of dough seem dry, dab with water.) Fold 1 corner of square diagonally over filling, leaving thin border of bottom dough layer exposed. Press layers of dough together securely around filling to seal. Lift each filled triangle and wrap back of triangle around top of index finger. Squeeze bottom corners of triangle together. Slide filled pasta off finger, transfer to prepared sheets, and cover with damp kitchen towels. Repeat with remaining pasta and filling. (Towel-covered sheets of tortellini can be wrapped with plastic wrap and refrigerated for up to 4 hours, or frozen; when completely frozen, tortellini can be transferred to zipper-lock bag and stored in freezer for up to 1 month. Do not thaw tortellini before boiling.)
3. FOR THE SAUCE: Heat pine nuts and butter in 10-inch skillet over medium-high heat and cook, swirling occasionally, until butter is melted and browned and releases nutty aroma, about 3 minutes. Off heat, stir in parsley and cover to keep warm.
4. Bring 4 quarts water to simmer in large pot. Add half of pasta and 1 tablespoon salt and cook, stirring often, until pasta is tender, about 2 minutes (3 to 4 minutes if frozen), adjusting heat as needed to maintain simmer. Remove pasta with slotted spoon and transfer to warm serving bowl. Add some of warm sauce to pasta, toss gently to combine, and cover to keep warm. Repeat with remaining pasta and transfer to serving bowl. Swirl 2 tablespoons of cooking water into remaining sauce, then add to pasta and toss gently to combine. Serve immediately, passing Parmesan separately.