The definition of eternity, they say, is two people and a ham. I’m recalling that wisecrack as I contemplate the Thanksgiving menu for my bubble of two. Cenk Sönmezsoy’s luscious pumpkin cheesecake has become a holiday tradition at our house, but it serves a dozen at least. My husband and I could polish it off, I have no doubt, but I’d rather take that option off the table. So I wanted to try to cut the recipe down—for my own sake and for those of you who might also be having a smallish gathering this year.