Preheat oven to 350°F and grease a 9×13-inch baking pan with nonstick spray. Set aside.
In a medium bowl, mix together the cake mix, eggs, oil, and eggnog. Pour into prepared pan and bake until a toothpick inserted into the center comes out clean, 20-25 minutes.
Once cake has cooled, poke holes all over cake using the end of a wooden spoon.
In a large bowl, whisk together pudding, brandy (if using), and eggnog. Before pudding has a chance to thicken, pour evenly over the cake. Place in refrigerator to chill for at least 15 minutes, but ideally one hour.
Gently stir cinnamon and nutmeg into whipped topping and spread evenly over the top. Slice, serve, and enjoy!
Note: If you don’t want to use brandy, use the equivalent amount of eggnog instead.