In a medium saucepan, heat the cream, milk, cinnamon stick, nutmeg, star anise, and cloves over medium heat, stirring occasionally, just until it comes to a boil.
Immediately turn off the heat and set aside to infuse at least 15 minutes.
In a large bowl, whisk the egg yolks with the sugar. Whisking constantly, gradually pour in the hot cream mixture. Whisk in the pumpkin puree. Pour the mixture into four ovenproof ramekins and arrange in a hot water bath.
Bake in the center of the oven until almost set but still a bit soft in the center, 30 to 40 minutes. The custard should jiggle a bit when you shake the pan; it will firm up more as it cools.
Remove from the water bath and cool to room temp (approx 20 mins). Refrigerate at least two hours, and up to 24 hours.
When ready to serve, preheat a broiler to very hot (or fire up your kitchen torch). Cover the surface of each creme brulee with a thin layer of coarse sugar. Place the ramekins on a baking sheet or in a roasting pan and broil until the sugar is melted and well browned, one to two minutes, or torch them! Cool for a minute before eating!