Soak the prunes in the sherry for 2-3 hours

In a lidded saucepan, simmer the prunes in the sherry until tender

Lift the prunes our of the saucepan using a slotted spoon and set aside to cool

Cut the prunes carefully down one side and remove stones (ignore this step if you bought pitted fruit)

Add the damson jam to the liquor and set on a low heat to melt, whisking and straining at the end, if necessary, to get a smooth glaze

Using a food processor, pulse together the flour, ground almonds and caster sugar with the cold cubes of butter. When the mixture looks uniformly crumbly, add the egg yolk and sprinkle a tablespoon of cold water evenly over the top and continue to pulse until the mixture comes together into a ball. Add another tablespoon of water if necessary

Cool the ball of pastry, in a zip-lock bag, in the fridge for half an hour to an hour

Roll out the pastry and line a 18-20cm/7-8" diameter flan dish

Set aside to cool

In a small saucepan, mix the custard powder and milk to a paste. Using a wire whisk, stir over a gentle heat until boiling

Tip into a steep-sided mixing bowl and whisk well

When well cooled, whip the double cream, sweeten with the sugar and fold into the custard

Using a (mini) food processor, pulse together the ground almonds, caster sugar and egg white until it forms a ball

To bring everything together

Carefully stuff each prune with about a teaspoon of the marzipan

Fill the cooled flan case with the custard cream mixture, spreading it evenly

Arrange the filled prunes evenly over the top of the custard cream trying to cover it completely

Brush or spoon the glaze over the top

Slice and serve