Warm the milk and cinnamon in a pot at low heat, let it stand for a short time. Remove the cinnamon. Divide the chocolate into pieces and dissolve in the hot milk while stirring. Pour the chocolate mixture into a large mixing bowl and let it cool down for about 45 minutes.
Whip the cream in portions until stiff and fold into the chocolate mixture. Pour into a serving bowl, cover and leave to cool for approx. 3 hours.
Crumble the speculum. Sprinkle mousse with it. Serve with caramel cream.