Melt the panna cotta and add the coffee beans. Leave to infuse for 30 minutes and pass through a fine sieve. Pour into the glasses and leave to set in the refrigerator.
For the foam, mix all the ingredients and pour into a 500 ml siphon. Aerate with a gas cartridge and store in the refrigerator.
For the jelly, bring the coffee and liqueur to the boil and add the pre-soaked gelatine. Cool down to room temperature and pour the jelly on top of the set panna cotta.