Allow ice cream to warm up a bit if too hard to scoop straight out of the freezer. Allow to sit for no more than 5 minutes.
Using a small cookie scoop, scoop eggnog ice cream and place on one cookie. Top with another cookie. Do not allow to melt! Immediately place in freezer or make them up as they are being served.
Freeze in an airtight container in the freezer for no more than a month. If serving from freezer allow to sit for a minute to soften slightly.