Preheat oven to 325 degrees F.
Separate eggs. (Use the whites for a meringue or to make an egg-white omelet.)
In a medium-size bowl, add the sugar and cinnamon, then whisk in the hot coffee and the egg yolks until the mixture is soft yellow and creamy.
Using a medium saucepan, gently stir together the heavy cream and the half-and-half, then add the vanilla bean. Heat over a medium flame until the liquid scalds (a skin will form on top of the cream combo). Pour one-third of the scalded cream over the egg mixture, whisking to combine them.
Next, return the egg yolk and cream mixture into the saucepan, and whisk it together with the plain cream. Strain through a medium mesh strainer into a pitcher. Discard the vanilla bean.
Make a water bath by filling a 9″x12″ baking pan with hot water so that it reaches about halfway up the sides. Pour the custard mixture into six six-ounce custard cups or ramekins and gently put the cups into the water bath pan. Bake for 60 minutes, or until the surface appears set around the edges but the centers are still somewhat liquid. The custards will be faintly “custard yellow”.
Using a long pair of tongs, remove the cups from the water bath and set on a wire rack to cool completely.
To serve, preheat the broiler and place the custard cups on a baking sheet. Sprinkle a little sugar evenly over the entire surface of each custard cup. Place the baking sheet on the rack closest to the heating element for just a few seconds. Remove immediately and serve.
(If you have a culinary blowtorch you can use that, too, to achieve the classic crisp sugar crust.)
