2 tsp instant coffee granules
140g/5oz plain flour, plus extra for dusting
140g/5oz caster sugar, plus extra for dusting
25g/1oz icing sugar, plus extra for dusting
160驳/5戮辞锄 walnut halves
3 tbsp unsalted butter, melted, plus extra for greasing
170ml/6fl oz double cream
4 free-range eggs