Beat eggs, sugar, molasses, cinnamon, ginger, nutmeg and salt. Mix in pumpkin and half-and-half. When it is smooth, put it in buttered baking dish, which you then put into a bain-marie: put dish into larger baking dish, and fill larger dish with hot water to about 1” below the rim of the custard dish. Bake for 50 minutes and start to check it. You want a set, firm custard, so that a knife inserted into the center comes out clean. Cool and refrigerate overnight.