Start by making a raspberry jam. Cook together the raspberries and sugar for 15 minutes then allow to cool down. Place the chocolate sponge and place into the bottom of a deep lined tin or ring. Spread the chocolate & hazelnut spread on top.  Melt the soaked gelatin, mix into the cooled jam and then mix the jam into the whipped double cream. Immediately spoon this mixture into the ring over the chocolate sponge. Smooth out the top perfectly and place into the fridge to set for 1 hour. Meanwhile, melt together the 100ml cream and 100g chocolate to make a ganache and pour on top of the mouse and spread out. Once set, remove the mousse cake from the tin or ring and decorate the top with fresh raspberries and mint leaves.