Place heavy cream, grated nutmeg, and allspice in a large mixing bowl with a fine mesh strainer on top. Set aside.

In a medium saucepan, combine milk and vanilla. Cook over medium heat, swirling occasionally, until bubbles form around the sides and the milk starts steaming.

In another mixing bowl, vigorously beat together the eggs, yolks, sugar, and salt for approximately 3-5 minutes until the mixture is thickened and pale.

Add in the warm milk in a slow stream, whisking constantly to incorporate.

Pour the mixture back into the saucepan and cook over low heat, stirring constantly with a wooden spoon for about 6 minutes, or until the mixture reaches 165°F as read on a cooking thermometer.

Immediately strain into the mixing bowl with the heavy cream.

Place in refrigerator uncovered and allow the eggnog to cool completely for at least 2 hours.

To serve, you can beat the egg whites until stiff peaks form, slightly sweetening them. Pour the eggnog into a glass, add a generous dollop of the whites, then as a final flourish, you can take a hand torch and lightly torch the whites.