Cranberry, hazelnut and sherry tart

1 Preheat the oven to 180ºC, gas mark 4. Roll out the pastry to 0.5cm thick and use to line a 24cm fluted tart tin. Prick the base with a fork, leaving the excess overhanging. Line with baking parchment, fill with baking beans and blind-bake for 25 minutes. Remove the paper and beans. Bake for 10 minutes, or until starting to brown. Trim the excess pastry with a knife. 

2 Meanwhile, put the hazelnuts on a tray and bake for 5-10 minutes until a shade darker. Cool, then pulse in a food processor until finely chopped. Transfer to a large bowl. Put the butter, caster sugar, vanilla, lemon zest and a good pinch of salt in a food processor. Whizz until light and fluffy. Add to the nuts with the eggs, flour and sherry. Beat until fully combined. 

3 Transfer the mixture to the pastry case and smooth out. Scatter over the cranberries (no need to defrost if frozen) and demerara sugar. Bake for 25 minutes, or until the tart is golden and firmed up at the edges but retains a little wobble in the centre. Cool completely, then remove from the tin and serve with cream, if liked. If making ahead, cover and chill for up to 2 days. Remove from the fridge 20 minutes before serving to bring to room temperature