In a medium saucepan, whisk together the heavy cream, cloves, cinnamon sticks, fresh ginger, ground ginger, nutmeg, and salt. Heat the mixture over medium-low heat, stirring occasionally, until it reaches just below boiling, about 10 minutes.

Remove the saucepan from the heat, and add the vanilla extract. Cover the pot with a lid and let the mixture steep for 20 minutes.

While the cream mixture is steeping, preheat your oven to 325°F (175°C). Prepare your mixing area by setting out the egg yolks and granulated sugar.

In a mixing bowl, whisk the egg yolks and granulated sugar together until smooth and pale in color.

Carefully strain the steeped cream mixture through a fine-mesh strainer into the bowl containing the egg yolks and sugar. Gradually whisk the warm cream into the egg mixture.

Evenly distribute the custard mixture among six 4-ounce mason jars.

Place the filled mason jars into a baking dish. Carefully fill the dish with boiling water until it reaches halfway up the sides of the jars.

Bake the custards in the preheated oven for 30 to 40 minutes.

Once baked, carefully remove the jars from the water bath and allow them to cool for 60 minutes. After cooling, refrigerate the jars for a minimum of 4 hours.

Just before serving, sprinkle a thin, even layer of granulated sugar on top of each chilled custard and caramelize the sugar with a kitchen torch.