Yield: Serves 8-12, depending on cup size.
Separate your eggs, putting the yolks in a large bowl and the whites in a clean, airtight container to freeze until needed.
Add the sugar to the egg yolks and whisk until blended, creamy, and pale yellow.
Slit your vanilla bean lengthwise and scrape the seeds into the milk in a heavy saucepan, and drop in the empty pod. Add the pumpkin pie spice and bring to near a boil. Let cool and remove vanilla pod.
Pour the milk, 3/4 cup of the heavy cream, and all the booze into your egg yolk mixture. Add a pinch of salt and whisk vigorously until fully incorporated. Pour the eggnog base into a sealable container (empty milk jugs are perfect) and place in the fridge to age for a week (or as much of a week as you can wait).
The day before you want to serve the eggnog, transfer the egg whites to the fridge to thaw.
An hour before serving, take the egg whites out of the fridge to come to room temperature. Place the whites in a very clean metal or glass bowl. Using an electric mixer or stand mixer, whisk the whites at high speed until soft peaks form, about two minutes. Pour egg whites into serving bowl.
Place the remaining cream in the mixing bowl (no need to wash the bowl), and whisk on high speed until medium peaks form, about 2 minutes. Add to the whipped whites in the punch bowl, stirring very gently.
Shake the eggnog base to recombine, then carefully pour it into the serving bowl. Gently whisk the eggnog together until just combined. Do not over-whisk or you'll deflate the egg whites. Grate a little nutmeg on top and serve chilled, either over ice in each glass or keeping the serving bowl in a larger bowl of ice.
Keep a whole nutmeg and small grater next to the serving bowl, so each glass can be individually topped with fresh nutmeg. You can use any combination of bourbon, brandy, rum, or other liquors in this recipe, as long as the total alcohol is around 2 cups.