Step 1

For the dough, combine the milk, half the sugar and the yeast in a jug. Add the egg and lightly beat to combine.

Step 2

In a large bowl, mix the flour, salt, cardamom and the remaining sugar until well combined. Add the milk mixture and combine. Knead in the bowl until you have a smooth dough.

Step 3

Rub about 10g/¼oz of the butter onto a clean work surface. Tip the dough out and knead in another 20g/¾oz butter until well combined and the dough forms a smooth ball. Transfer the dough to a lightly buttered bowl and cover with cling film. Prove in a warm place until doubled in size.

Step 4

For the glaze, heat the caster sugar and 112ml/3¾fl oz water in a saucepan. When the sugar has dissolved, set it aside to cool.

Step 5

Tip the dough out onto the work surface and roll out into a rectangle approximately 26x35cm/10½x14in.

Step 6

Spread the remaining butter on the dough and sprinkle over the chocolate and hazelnuts. Roll it up like a sausage and pinch the edges together to seal. Using a sharp knife, cut the dough lengthways to make two strands. Pinch the two pieces together at one end and then tightly braid together. Transfer to a loaf tin, cover with a proving bag and put in a warm place to prove until doubled in size.

Step 7

Preheat the oven to 190C/170C Fan/Gas 5.

Step 8

Whisk the egg yolk with 2 teaspoons water then brush onto the proved loaf.

Step 9

Bake for 27 minutes, or until golden-brown. Leave to cool a little in the tin, then brush the sugar syrup onto the loaf. Remove from the tin and leave to cool completely on a wire rack.