1. Preheat the oven to 150C.

2. Add 150g of blackberries and one tablespoon of castor sugar to a bowl and mash with a fork until the berries break down and release their juices. Set aside.

3. Break the chocolate into a medium-sized bowl.

4. Add the milk and cream to a saucepan over medium heat. Bring to the boil then add the sugar and stir briefly to dissolve, before pouring over the chocolate. Whisk until the chocolate has melted and fully incorporated. Cool slightly before whisking in the vanilla bean paste, and the eggs and yolk.

5. Using a rolling pin, roll out the pastry sheet to 5 millimetres thick and use it to line a 28-35-centimetre round tart tin. Line the tart shell with baking paper and fill with rice or baking beads. Blind bake in the oven for 15 minutes, remove the baking paper and rice, and return to the oven for a further five minutes.

6. Reduce the oven temperature to 115C. Remove the tart from the oven, smear the base of the tart shell with the blackberry mixture then carefully pour the chocolate mix over the top. Bake for 25 to 35 minutes, or until the chocolate filling has set – it should wobble but hold its shape.

7. Remove and cool to room temperature. Finish with fresh blackberries and serve with cream or ice-cream (if using).

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