Preheat oven to 300°F. Place six 4-ounce ramekins in a baking dish.

Place Irish cream and vanilla in a large measuring cup with a pour spout.

In a medium bowl, whisk together egg yolks and sugar until light, about 1 minute.

Heat salt, cream, and milk in a medium saucepan over medium heat, stirring often, until just barely simmering.

While whisking the egg mixture rapidly, slowly pour in hot cream. Strain mixture into the Irish cream and stir to combine.

Divide mixture among the six ramekins and sprinkle each with nutmeg.

Heat about 4-6 cups water until boiling.

Place baking pan with ramekins in the oven and pour hot water into the baking pan until it comes halfway up the sides of the ramekins.

Bake 25-30 minutes, or until set but still slightly jiggly in the center. Remove from oven and let ramekins stand in the hot water for 5 minutes, before removing to a wire rack to cool completely.

Cover and refrigerate completely, about 4 hours.