Preheat the oven to 190°C, fan 170°C, gas mark 5 and place a baking tray in the oven to heat up.
Line a 20cm tart tin with the pastry, prick the base with a fork, and chill in the fridge while you prepare the tart mixture.
Whiz the hot cross bun pieces in a food processor until you have breadcrumbs,then transfer to a bowl.
Pour the golden syrup into a small pan, and place over a gentle heat. Bring to a simmer then pour over the breadcrumbs, and add the egg, orange zest, ginger, cinnamon and cream. Stir to combine.
Remove the pastry case from the fridge and pour in the filling mixture. Carefully put the tart onto the preheated baking tray and cook for 35 minutes, until golden.
Serve with a dollop of crème fraîche.