Line a 20cm square baking tin with a strip of baking parchment – leave an overhang as this will help lift everything out of the tin later. Scatter the amaretti biscuits over the base of the tin and set aside.
Tip the chocolate into a heatproof bowl and pour the cream into a saucepan. Bring the cream to the boil, then pour it over the chocolate and stir until completely melted. Pour the mixture over the biscuits, then tap the tin to even out. Cover with cling film and chill in the fridge for at least 4 hrs (or up to 2 days ahead).
While the chocolate is setting, drain the cherries over a small saucepan and set them aside. Simmer the juice from the tin for about 5 mins or until syrupy. This can be done a day ahead and both can be kept in the fridge.
To serve, use the parchment handles to lift everything out of the tin on to a board and, using a sharp knife dipped in hot water, cut into six neat bars. Using a pastry brush, paint a thick stripe of the kirsch syrup across each plate, then sit a chocolate bar across the stripe at an opposing angle. Top each bar with a line of cherries and serve with extra syrup on the side.