Preheat the oven to 350° and butter a 2 quart baking dish.
Add the croissants to the prepared dish and toss to combine. Sprinkle the pecans over top.
Add the melted ice cream, milk, sugar, eggs and cinnamon to a large bowl and whisk to combine.
Pour the custard over the croissants and press to ensure all bread is submerged and some pecans sink into the bread. Let the mixture sit for about 30 minutes so the bread can soak up the custard.
Bake for 50-55 minutes or until the top is browned and the bread pudding is set.
Allow to cool for 10 - 15 minutes before serving. Serve with additional Ben & Jerry's Ice Cream if desired.