Heat the milk, cream, pumpkin puree, cinnamon, and molasses over low heat until very hot, but not boiling. Combine the eggs, egg yolks, and granulated sugar in a stainless steel mixing bowl or the top of a double boiler. Pour the hot milk mixture into the egg mixture a little at a time, whipping constantly.
2
Place the mixing bowl over a pot of boiling water and continue to whisk until the mixture is thickened (about 12 to 15 minutes.) It should boil slightly. Spoon the mixture into six 6-ounce custard cups and chill.
3
Just before serving, preheat the broiler. Sift the brown sugar over each cup and place the cups in a pan filled with ice. Place the entire pan under the broiler and cook until the sugar has formed a crisp crust. Serve immediately.