Preheat your oven to 350°F (180°C) and grease a 9x13 inch baking dish.

In a large mixing bowl, combine the granulated sugar, vanilla extract, ground cinnamon, ground nutmeg, and salt. Whisk until well-mixed. Add the eggs one at a time, whisking thoroughly, then gradually pour in the eggnog.

Place the cubed bread evenly into the prepared baking dish and pour the custard mixture over it. Toss gently to ensure even saturation.

Press down the mixture gently and cover with aluminum foil. Allow it to rest for 30 minutes at room temperature.

Remove the foil and bake for 45-55 minutes, until golden brown and a knife comes out clean.

Let it cool for 20-30 minutes, dust with powdered sugar, and serve warm with whipped cream or eggnog sauce.