Chop croissants into 1- to 2-inch pieces and place in buttered 9x13 baking or casserole dish.

In a large saucepan over medium heat, whisk cream, milk, sugar, salt and Irish cream together; bring to a gentle simmer. Do not boil. Remove from heat.

In a medium bowl, crack eggs and whisk slightly. Slice vanilla bean pod lengthwise to expose beans; scrape beans into mixture with a spoon or knife. Carefully whisk hot cream mixture into eggs to temper them.

Pour warm custard mixture over croissants. Sprinkle with dark chocolate and bake at 350°F for 45-50 minutes until golden brown. Serve warm with French vanilla ice cream.