– In a medium saucepan over low heat, melt brown sugar, milk, butter, cinnamon stick, vanilla and dark rum. – In a small bowl, whisk your eggs. Slowly add into the eggs some of the warm milk mixture, couple tablespoons at a time while whisking the eggs. Add the egg mixture into the remaining custard. – Carefully pour your custard over the croissants and fold the bread to ensure all of the bread is fully coated. – Cover your custard bread mixture and allow it to rest for 10 minutes.  – Pour half of your bread into a greased 9x9 casserole dish and sprinkle with half of your chocolate chips. Top with the remaining bread pudding and chocolate chips. – Cover with tented aluminum foil and bake for 30 minutes. Uncover the bread pudding and bake for 15 minutes. – Place the heavy cream, white sugar, and butter in a sauce pan. When sugar has dissolved, add in the rum. Pour the warm sauce over each slice of bread pudding before serving.