I searched many recipes for this iconic little pastry and settled on this history lesson from The Guardian.

Makes 25
Pastry:
250g flour
250g cold butter, diced
1 tsp salt
120ml cold water

Filling:
120g currants (I used raisins cos that's what I had on hand, you can also use sultanas)
50g mixed peel
zest and juice of 1/4 lemon and 1/4 orange
1 tbsp brandy, rum or liquer of choice
50g butter
40g light brown/muscovado sugar
1/4 tsp nutmeg
1/4 tsp allspice (or a mix of cinnamon and ginger)
egg white
demerara sugar to sprinkle

In a small bowl mix the currants, peel, zest, juice and brandy and set aside.

In a food process or by hand, mix the flour and salt. Add in the butter and blitz until flaky. Slowly add in the water and mix until a dough is formed but don't overwork it.

Roll out the dough on a floured surface into a rectangle three times as long as it is wide. Fold down the top third into the middle, then fold up the bottom over it. Rotate the dough 90 degrees. Repeat the rolling and folding, then wrap dough in cling film and chill in fridge for 20 mins. Repeat whole rolling process again and return to the fridge for an hour.

Preheat the oven to 200C. Line a baking tray with baking paper.

Cream the butter and sugar until smooth then mix in the fruit and spices. Roll out the dough to 4mm thick and cut into rounds approx 9cm in diameter. Place a teaspoon of filling into the centre of each circle. Brush the edges with water and bring in the edges and pinch together to seal. Place sealed side down onto the baking tray, pressing down gently to form a little disc. Repeat until all the pastry is used. 

Brush with egg white and sprinkle with demerara sugar if desired. Make 2 or 3 small cuts on top of each pastry with a sharp knife.

Bake for 20-25 min, rotating the tray halfway for even cooking. Leave to cool on the tray for 10 min and store in an airtight container when completely cooled.