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

1. Preheat Oven: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking dish with butter or cooking spray.
2. Prepare Croissants: Tear the croissants into bite-sized pieces and distribute them evenly in the greased baking dish.
3. Mix Wet Ingredients: In a large bowl, whisk together the eggs, eggnog, whole milk, sugar, vanilla extract, nutmeg, cinnamon, and salt until well combined.
4. Combine: Pour the egg mixture over the croissants, ensuring that all pieces are soaked. Gently stir to combine, but do not overmix.
5. Add Fruits: If using, sprinkle raisins or dried cranberries over the mixture for added flavor and texture.
6. Bake: Place the baking dish in the preheated oven and bake for 45-50 minutes, or until the top is golden brown and a toothpick inserted in the center comes out clean.
7. Cool: Once baked, remove from the oven and let it cool for about 15 minutes before serving.
8. Serve: Optionally, dust with powdered sugar or drizzle with caramel sauce just before serving.

These steps will guide you in creating this amazing Rich Eggnog Croissant Bread Pudding effortlessly.