Place the sugar, water and glucose in a thick-bottomed pan. Warm the cream in a separate pan

Cook the sugar mix until a dark caramel is reached, then reduce the heat and slowly add the warm cream, beating smooth after each addition

Make sure all the caramel is dissolved into the liquid, then take off the heat. Whisk in the salt and the butter. Pour through a fine sieve and cool quickly

Once the filling mixture is chilled, pipe into the dark chocolate shells. Make sure you fill each one up to the lip of the shell

Allow to set, then join each shell half together with some of the melted dark chocolate (leave some for the rolling). Leave to set again on baking parchment

Finally, roll the bon-bons in the melted chocolate and then in cocoa powder to finish