In a pan, add the sugar and melt over a medium heat, stirring occasionally until it turns a rich caramel colour
Add the hot cream and salt while whisking. Remove from the heat then add the cold cream. Let cool then add the bergamot oil.
Pour the mousse into a siphon charged with nitrogen and set aside in the refrigerator.
Line a baking tray with parchment paper.
Combine the sugar and water in a pan and cook to 115°C.
Add the almonds and hazelnuts and continue to cook while stirring, until the sugar has melted and caramelised. Add the butter, then spread the mixture on the lined baking tray and let cool.
Put the chocolate in a bowl and set over a pan of simmering water. Stir until melted then remove from the pan.
In a separate pan, gently heat the whipping cream. Gradually incorporate the hot cream in three stages, while stirring, until fully combined.
Dust one side of the plate with cocoa powder, then carefully pipe dots of chocolate sauce on the other side of the plate.
Delicately stamp a round hole at the top of the sphere with a 4 cm round cutter. Use the cut-out chocolate as the bottom base for the sphere.
Using cotton wool, gently apply the golden lustre to the sphere.
Fill the sphere halfway with the caramel mousse, then top with the nut brittle. Fill the sphere with more mousse, then top with extra nut brittle.
To finish, decorate with a gold leaf.