Remove bread crusts and cut each slice into four triangles.
Melt chocolate, cream, rum, sugar, butter, and cinnamon in a bowl over simmering water.
Remove from heat and stir until ingredients are thoroughly amalgamated.
Whisk eggs in a separate bowl and blend in the warm chocolate mixture.
Spoon 1.5cm of chocolate mixture into a buttered dish and layer half the bread.
Pour half the remaining chocolate over the bread and layer the remaining triangles.
Top with remaining chocolate and press bread down gently with a fork.
Chill covered between 24 and 48 hours in the refrigerator.
Preheat oven to 180°C and bake for 30 to 35 minutes.
Rest for 10 minutes before serving with chilled double cream.