You can make this as one big trifle or use pretty glasses to make it into individual servings. But however you present it make sure you use the best quality sherry for the tastiest result.
1. Cut the sponge in half horizontally and fill with jam, then cut it into large cubes and put in a pretty glass bowl.
2. Spoon sherry or liqueur over the sponge, then arrange the fruit and any syrup over the top. Set aside while you make the custard.
3. Mix the custard powder, sugar and ¼ cup of the milk to a smooth paste. Add the remaining milk and cook over a low heat, stirring constantly until mixture boils and thickens.
4. Remove from the heat, cover and leave until cool, then pour the custard over the fruit. Chill for 1 hour then cover with whipped cream and toasted almonds, or other decorations.