In a small pot, combine heavy cream, cloves, cinnamon sticks, fresh ginger, ground ginger, nutmeg, and salt. Heat over medium-low for about 10 minutes until bubbling. Remove from heat, add vanilla extract, cover, and let sit for 20 minutes.

Preheat oven to 325°F (175°C). Gather equipment including a mixing bowl for egg yolks and sugar.

In a mixing bowl, whisk egg yolks and granulated sugar until smooth and pale, about 2-3 minutes.

Strain the cream mixture through a fine-mesh sieve into a measuring cup to remove solids.

Gradually whisk the strained cream into the egg yolk mixture slowly to prevent cooking the eggs.

Pour the custard mixture evenly into six 4-ounce mason jars, filling about three-quarters full.

Place jars into the oven within a baking dish. Fill the dish with boiling water halfway up the sides of jars. Bake for 30-40 minutes until custards are set but jiggle slightly.

Cool jars at room temperature for 60 minutes. Then cover and refrigerate for at least 4 hours or up to 2 days.

Before serving, sprinkle granulated sugar over custards and caramelize the sugar using a kitchen torch or oven broiler.