In posh restaurants, zabaglione used to be made in front of you at the table. I've replaced the classic masala here with Kingston Black, an apple apéritif made by Julian Temperley (ciderbrandy.co.uk).
For the zabaglione
4 medium egg yolks
3tbsp caster sugar
120ml Kingston Black
To make the zabaglione, put the egg yolks and sugar in a round-bottomed steel or Pyrex bowl (not aluminium or it may go a grey colour). Beat well with a whisk for 2-3 minutes, then beat in the Kingston Black.
Hold the bowl with a cloth and fit it over a pan containing 3-4cm of simmering water. Whisk continuously for a few minutes (use an electric whisk if you prefer) until the mixture is thick and frothy.
To serve, put the Tayberries in bowls or plates and pour over the warm zabaglione.