Penne with Pumpkin or Squash

I love filled pasta, but I rarely have the time or energy to make it. So, when I became enamored of pasta con zucca—a raviolilike affair stuffed with the Italian equivalent of pumpkin—I created this alternative, which is not quite as elegant but tastes just as good. If you cannot find a small pumpkin—the only kind whose flesh is dense enough for this dish—use butternut squash. Peel either with a paring knife; their skins are too tough for vegetable peelers.