I've never had advocaat and I actually have specifically designed advocaat glasses (in a metal holder) that I've been meaning to use for years. Along with the glasses (which I received as a Christmas present) I got two recipes from one of my parent's friend's grandmothers (last name Braaksma - can't get much more Dutch than that).
Here they are (if you try them before me please post the results:
Advo-kat - 1st Recipe
10 eggs
1 cup sugar
1 cup vodka
1 package vanilla suiker (apparently available at the Dutch store of which there are many in West Michigan, maybe you can find it in Andersonville?)
Mix all ingredients in a saucepan. Cook slightly without boiling, stir often. Cool to room temp and serve with whipped cream.
Advo-kat - 2nd recipe
12 eggs
2 packages vanilla suiker
1 cup sugar
1/2 bottle vodka
Beat the eggs in a medium bowl. Add the remaining ingredients and cook in a double boiler (or over boiling water), don't boil. Stir constantly. Cool and serve.
They don't seem much different, the second one looks to be stronger. I haven't tried either method and don't know how easy it would be to find vanilla suiker here.