Prepare the raspberry sauce so it has time to cool before preparing the raspberry mousse. Place raspberries, sugar and lemon juice in a small saucepan and place over medium heat, bring to a boil and cook for about 10 minutes until slightly thickens. Remove from heat and sieve to remove seeds. Set aside while you prepare the gelatin.
Dissolve gelatin in cold water and let it swell for about 5 to 10 minutes. Add the gelatine over the warm raspberry sauce and stir to dissolve. Let the raspberry mixture cool at room temperature while you prepare the rest.
Prepare the cocoa brownie. Preheat the oven to 350F (180C). Grease and line a 8 inch (20cm) springform pan with parchment paper.
In a bowl whisk egg with sugar until well combined. Incorporate oil and vanilla extract.
Sift the flour, salt and cocoa powder and whisk to fully incorporate.
Pour the batter into the prepared pan.
Bake for 10-12 minutes until a toothpick inserted into the center comes clean or with few moist crumbs attached.
Let cool completely.
Prepare the chocolate raspberry crunch. Melt milk chocolate, semisweet chocolate and butter over bain-marie. Let cool slightly.
In a medium bowl combine cookie crumbs with paillete feuilletine and freeze-dried raspberries if used. Add melted chocolate and stir to combine.
Spread the crunch on top of the cocoa brownie leaving a 1/2 inch (1cm) border and refrigerate until you prepare the mousse.
Prepare raspberry mousse. Whip the chilled whipping cream until stiff peaks form. Add the cooled raspberry mixture and mix until well combined.
Line an acetate sheet around the cake and pour the mousse over the cake. Smooth the top.
Refrigerate for at least 4-6 hours or overnight.
Prepare the chocolate glaze.
Place chocolate and cream in a heatproof bowl and place over a pan with simmering water. Melt over low heat.
Remove the cake from the pan and place it over a rack or simply on a smaller pan placed over a parchment paper lined baking sheet to collect the excess. Pour the glaze on top and edges of the cake. Use an offset spatula to remove the drips and decorate the bottom of the cake with chopped chocolate. Transfer the cake to a serving platter and refrigerate for 20-30 minutes.
Prepare chocolate raspberry shards, optional. Melt 2.5 oz (70g) semisweet chocolate over bain-marie. Remove from heat and add 1 oz (30g) chopped semisweet chocolate for tempering. Stir until melted.
Spread chocolate evenly into about 9 x 6 inch (23x15cm) rectangle on a parchment paper lined baking sheet. Sprinkle some freeze-dried raspberries and coconut flakes on top of the chocolate.
Refrigerate to set.
Cut with a sharp knife in different shapes. Refrigerate until ready to decorate the cake.
Decorate the cake with fresh raspberries, dust with powdered sugar, add chocolate raspberry shards and fresh mint. Enjoy!