This is my go-to dessert when I have very little time to make anything, but I still want to give everyone a treat. These take just 15 minutes to prepare and 15 minutes to chill, and you can make them a day ahead.
Technique tip: Don't over whisk the mixture as it will be too runny.
Swap option: You can swap the coffee extract for vanilla or rosewater.
Place the dark chocolate in a heatproof bowl set over a saucepan of simmering water and allow it to melt, then remove from the heat. Stir in the caster sugar and coffee extract and crack in the eggs. Using a hand-held electric beater, whisk for 5 minutes. Finally, whisk in the mascarpone for a few seconds, until smooth.
Divide between four 9-fluid-ounce serving glasses and chill in the fridge for 15 minutes before serving.