Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking dish.
In a large mixing bowl, whisk together eggnog, eggs, whole milk, sugar, vanilla extract, cinnamon, nutmeg, and salt until smooth.
Add the donut pieces to the custard mixture, stirring until all donuts are soaked.
Let the mixture rest for about 10-15 minutes.
Pour the soaked mixture into the prepared baking dish, spreading it evenly.
Bake for 40-50 minutes until the top is golden brown.
Let it cool for about 10 minutes before serving.
Serve warm with whipped cream and a sprinkle of cinnamon or nutmeg.
Notes
For best results, use fresh donuts and ensure to whisk the custard mixture thoroughly. Allowing the donuts to soak properly will yield a moist pudding.