In a cocktail shaker, combine the espresso, vodka, coffee liquor and eggnog. Add ice to fill the shaker halfway up.
Place the shaker lid on tightly and shake vigorously for about 30 seconds, until the outside is cold and frosty.
Strain the mixture into two martini glasses, dividing the mixture evenly among the two glasses.
Grate a bit of nutmeg over the top of each martini and place 3 espresso beans on top of each.