Grate the dark chocolate and melt in a bain-marie, first melting 2/3 of the amount and then adding the rest of the chocolate. Pour the melted chocolate into a piping bag and pipe small hearts onto a sheet of baking paper. Then leave the chocolate hearts to cool.
Boil the chestnuts in water for approx. 30 minutes until soft. Then peel them.
Puree the peeled chestnuts in a blender or with a hand blender together with milk and honey to a creamy consistency. Pour into a piping bag and pipe the chestnut cream into glasses.
Whip the cream until stiff, fill into a piping bag with a star-shaped nozzle and pipe onto the chestnut cream.
To serve, sprinkle the cinnamon over the cream using a sieve and garnish with the chocolate hearts.