Preheat oven to 350°F. In a small bowl, toss together cookie crumbs and sugar with melted butter. Press firmly onto bottom and halfway up sides of 9-inch or 10-inch deep dish pie pan. Bake for 10 minutes or until lightly golden and set. Cool completely.
In a large mixing bowl, using an electric mixer whip together Dream Whip with 1 cup eggnog. Whip on high speed for 6 minutes or until soft peaks form.
Add remaining eggnog, pudding mix and rum or vanilla extract (Add rum, if using). Beat until blended on low then increase speed and beat for 2 minutes on high.
Spread eggnog custard into cooled crust. Cover and chill overnight or until set.
Decorate the top of the eggnog pie with whipped topping, and dust with nutmeg or ground cinnamon before serving. Store leftovers chilled.
Notes
What is Dream Whip? Dream Whip has been around for decades. It's a dry whipped topping mix that makes the filling of this pie truly dreamy. It's important and shouldn't be replaced, as it also serves to stabilize the filling. It can be found on the baking aisle of most grocery stores including places like Walmart and Target.
Substitutions: My preference is to use crushed Vienna Fingers for the pie crust, but any similar vanilla sandwich cookie will work. You could also use gingersnaps, graham cracker crumbs or vanilla wafer crumbs for a flavor twist.
Variations: You can replace the rum extract with 2-3 tablespoons of rum. Rum extract doesn't contain alcohol and keeps this eggnog custard pie family-friendly.