- Boil Cider in large skillet until reduced to 1/2 cup, about 18 minutes.
- Add cream; boil until slightly thickened, about 2 minutes. Transfer to bowl.
- Whisk in butter and both extracts. Cool slightly, then chill until cold, at least 1 hour. (Can be made 1 day ahead. Keep chilled.)
- Place 1 slice of cake on each plate. Top each with ice cream, sauce and nuts. The rich, creamy sauce is also delicious on crisps, puddings and cobblers.