1. Fill a medium stockpot a quarter of the way full with water. Bring to a boil, then reduce heat and let simmer. Fill a large bowl with ice water; set aside. Combine sugar and egg yolks in a large metal bowl, and whisk until mixture is pale and has a thick consistency, about 3 to 4 minutes. Add apple cider and brandy, and beat for 2 more minutes. (For best results, choose a metal bowl that just fits inside the pot.)

2. Set the bowl over the simmering water. Whisk together for 6 to 8 minutes, until the sabayon thickens and is fluffy and slightly stiff. The sabayon should begin to look satiny and start sticking to the bowl slightly; air bubbles will become very fine instead of large and loose.

3. Set bowl in ice-water bath. Continue whisking sabayon until chilled, about 3 minutes. Whip the cream to medium-stiff peaks, and fold into chilled sabayon. The sabayon can be stored in refrigerator for up to 24 hours.