Creating Rich Eggnog Croissant Bread Pudding is simple if you follow these steps:

1. Preheat the Oven: Set your oven to 350°F (175°C) and grease a 9×13-inch baking dish.
2. Prepare Croissants: Tear the croissants into bite-sized pieces and place them evenly in the greased baking dish.
3. Mix Wet Ingredients: In a large bowl, whisk together the eggnog, eggs, granulated sugar, vanilla extract, cinnamon, nutmeg, and salt until smooth.
4. Combine: Pour the eggnog mixture over the croissant pieces, ensuring they are well soaked. Gently fold in raisins or cranberries if using.
5. Let it Sit: Allow the mixture to sit for about 15 minutes to let the croissants absorb the eggnog mixture.
6. Bake: Place the dish in the preheated oven and bake for 45 minutes or until the top is golden brown and the center is set.
7. Cool: Remove from the oven and let it cool for 15-20 minutes before serving.
8. Dust with Powdered Sugar: If desired, dust the top with powdered sugar for a decorative touch.

Following these steps will guide you through the process of creating this incredible dish effortlessly.