Whisk the eggs and sugar together, continually, over a pan of boiling water till stiff. Allow to cool until just warm.
Whip the cream with the Poire William.
Line a 6" soufflé mould, around the outside rim, with a 3" strip of greaseproof paper so that 2" protrudes above the rim. Bind with sellotape.
Gently fold the flavoured cream into the eggs and sugar and pour into th