CRANBERRY, HAZELNUT AND SHERRY TART

Cranberry, hazelnut and sherry tart

500g block shortcrust pastry • 275g blanched hazelnuts • 200g unsalted butter • 175g golden caster sugar • 2 tsp vanilla bean paste or vanilla extract • 1 lemon, zest • 3 eggs, beaten • 4 tbsp plain flour • 3 tbsp sherry • 100g fresh or frozen cranberries • 3 tbsp demerara sugar