Prepare the liaison: In a medium bowl, whisk together egg yolks, sugar, and vanilla paste (or extract). Set aside.
Combine heavy cream, whole milk, sliced ginger, crushed cardamom pods, cinnamon stick, and ground cloves in a heavy-bottomed stainless steel or copper pot. Cook over medium-high heat, stirring constantly, until the mixture reaches 150°F (66°C).
Temper the eggs: While whisking continuously with one hand, slowly pour about ½ cup of the hot milk mixture into the egg yolk mixture at a time. Once you've added roughly half of the hot milk, quickly pour in the remainder of the liaison while continuing to whisk.
Add ½ to 1 ounce of your preferred spirit—brandy, whiskey, rum, bourbon, or Southern Comfort. For a non-alcoholic option, substitute with 1 teaspoon of rum extract or simply omit the alcohol.
Strain the mixture through a fine-mesh sieve into an airtight container or large mason jar. Cover and refrigerate for at least 24 hours before serving.
