1 tbsp plain flour
2 tbsp caster sugar
1 vanilla pod, halved lengthways, seeds removed
30g/1oz amaretti biscuits, crushed
100²µ/3Β½΄Η³ϊ dark chocolate, finely chopped
50g/2oz unsalted butter
500ml/18fl oz milk
80ml/2Β½fl oz Amaretto (or other almond liqueur)