Remove the crusts from the bread and cut each slice into 4 triangles, set aside.
In the top of a double boiler, combine chocolate, cream, rum, sugar, butter, and cinnamon, and place over simmering water. cook, stirring occasionally, until everything is completely melted. Set aside.
Whisk the eggs, then slowly add the chocolate mixture to them. spoon half of the mixture into a 7x9x2 baking dish. Arrange half the bread pieces in the next layer; repeat with chocolate and bread. Gently press the top layer down so it becomes covered with chocolate.
Cover the dish with plastic and allow to stand at room temperature for 2 hours, and then refrigerate for 24 or 48 hours.
When ready to cook, preheat oven to 350°F Bake on top shelf of oven til the top is crunchy, but the inside is soft, 30-35 minutes. Let stand 10 min before serving with whipped cream.