To make the syrup:
Combine 1 cup of water and brown sugar in a heavy medium saucepan. Bring to a boil over high heat, stirring until the sugar dissolves. Boil until the syrup reduces to 1 cup, about 10 minutes. Remove from the heat and whisk in the cream and cinnamon. Keep the syrup warm. (The syrup can be made 1 day ahead. Cool, then cover and refrigerate. Re-warm before serving.);
To make the bread pudding:
Lightly butter a 13 by 9 by 2-inch baking dish. Arrange the bread cubes in prepared dish.
In a large bowl, whisk the eggs, cream, milk, and sugar to blend. Pour the custard over the bread cubes, and press the bread cubes gently to submerge. Let stand for 30 minutes, occasionally pressing the bread cubes into the custard mixture. (Can be prepared 2 hours ahead. Cover and refrigerate.)
Preheat the oven to 350 degrees F.
Bake until the pudding puffs and is set in the center, about 45 minutes. Cool slightly.
Spoon the bread pudding into bowls, drizzle with the warm cinnamon syrup, and serve.