Pour eggnog into a medium saucepan, sprinkle the gelatin over the top, and let sit for about 1 minute.
Turn heat on medium-low and whisk your eggnog mixture until gelatin has dissolved.
Whisk in sugar, cinnamon, and nutmeg until sugar has dissolved.
Pour into small bowl and whisk in your vanilla, cover and refrigerate until mixture thickens up.
Once thickened slightly beat with your mixture to add some air and make it a little fluffy.
Fold in half your container of cool whip until blended, set aside.
In the bottom of 4 6oz cups or small bowls add 1/4 cup of your graham cracker crumbs, spoon the eggnog mousse over the top, repeat with remaining cups.
Place back into refrigerator and chill until set and firm.
Pipe remaining whipped topping over top and sprinkle with extra cinnamon if desired.