Preheat your oven to 350°F (175°C). Grease and flour the 9x13-inch baking pan.
In a large mixing bowl, combine the cake mix, eggs, 1 cup of eggnog, vegetable oil, nutmeg, and cinnamon. Use an electric mixer or whisk to blend until just combined and smooth.
Pour the batter into the prepared pan and spread it evenly. Bake in the preheated oven for about 30 minutes, or until a toothpick inserted into the center comes out clean.
While the cake is baking, prepare the eggnog liquid for the poke. In a small bowl, mix 1 cup of prepared eggnog and set it aside.
Once the cake is done baking, let it cool in the pan for about 10-15 minutes. Then use a skewer or fork to poke holes all over the cake, about 1 inch apart.
Pour the eggnog mixture over the warm cake, allowing it to soak in.
In another mixing bowl, combine 1 cup of whipped topping, 1/2 cup of eggnog, and vanilla extract to make the frosting. Mix until smooth.
Spread the eggnog frosting evenly over the top of the cake.
Chill the cake in the refrigerator for at least 1 hour before serving to allow the flavors to meld.
Before serving, garnish with a sprinkle of ground cinnamon and nutmeg for an extra festive touch.