Preparation time 30 minutes (plus refrigeration time). Cooking time 10 minutes.
1. Make jelly according directions on packet, cover; refrigerate until mixture is the consistency of unbeaten egg white.
2. Meanwhile, split cake in half horizontally though center; sandwich cake halves with jam. Cut cake into 3cm squares.
3. Place cake in 2.5-litre (10-cup) deep serving bowl; sprinkle with sherry.
4. Combine custard powder and sugar in medium saucepan. Gradually blend in milk; stir over heat until mixture boils and thickens. Remove from heat, stir in extract and ½ cup of the cream. Cover surface completely with plastic wrap; cool to room temperature.
5. Meanwhile, pour jelly over cake, cover; refrigerate until jelly sets.
6. Top jelly with peaches, then with custard.
7. Beat reaming cream in small bowl with electric mixer until soft peaks form. Spread cream over custard; refrigerate 2 hours or overnight. Sprinkle with nuts just before serving.
Tip: This recipe can be made a day in advance. The custard can be prepared in a microwave oven.