Preheat the oven to 180'C.
For the biscuit base: Melt the butter. Place the biscuits and the cocoa powder in a food processor and blend to a rough crumble texture. Remove from the blender and stir in the butter. Mix well and then spoon a 1 cm layer into the base of the glass. Transfer to the fridge and refrigerate for 10 minutes until set.
For the ganache: Bring the 320ml of double cream to the boil in a saucepan. Break the chocolate into small pieces if necessary and place in a heatproof bowl.
When the cream comes to the boil, pour the cream onto the chocolate and stir until all of the chocolate has melted and you have a glossy ganache. Allow the ganache to cool slightly for around 5 minutes.
In another bowl, lightly whisk the remaining whipping cream until it just begins to thicken.
Fold this cream into the ganache until evenly distributed. Transfer this mixture to a piping bag.
Remove the glasses from the fridge and spoon in the griottine cherries and some of the syrup.
Next, pipe in the chocolate mousse until the glass is almost full.
Place the glasses back in the fridge and refrigerate for at least 30 minutes to allow the mousse to set.
Spread the chopped almonds on a baking sheet and toast in the oven until lightly browned (about 5 minutes).
Cook the sugar in a saucepan over a low heat until it melts to a light golden caramel. Add the almonds and the butter and stir until completely absorbed.
Pour the nougatine onto a baking sheet lined with a silicone mat. Allow the nougatine to cool and become brittle. When brittle, break the nougatine into uneven shards.
Mix the cream, icing sugar and kirsch together in a bowl. Pour the mixture into a siphon. Screw the lid onto the siphon making sure it is tight. Shake the siphon vigorously for 10 seconds.
Charge the siphon with the compressed air and refrigerate until you are ready to serve.
Remove the trifles from the fridge. Top the trifle with the kirsch cream and finish with a shard of the nougatine tuile and a dusting of icing sugar.
«Vary the flavours in this trifle by using different fruits. Mandarin segments soaked in Grand Marnier will make a delicious alternative.»