1. Heat the oven to 200°C/180°C fan/400°F/Gas 6. Grease and line a 900g loaf tin.

2. To make the dough tip the flour into the bowl of a stand mixer fitted with the dough hook, add the yeast to one side of the bowl and the sugar and salt to the other side.

3. Make a well in the centre and pour in the eggs and milk, then mix on slow speed for 2–3 minutes, until firm.

4. Increase the speed to medium and add the butter, a little at a time. Mix well between each addition, allowing the butter to incorporate before adding more.

5. Once you have added all the butter, continue kneading with the dough hook on medium speed through the sticky stage, until you have a ball of smooth, silky, shiny dough. Transfer to a lightly oiled bowl, cover and chill in the fridge for 2 hours.

6. Meanwhile, make the filling, place the butter, date syrup and chocolate in a pan and melt very slowly over a low heat, stirring until smooth and combined. Remove from the heat and whisk in the cocoa powder. Pour into a bowl and leave to cool, then chill in the fridge until thickened and spreadable.

7. Lightly flour a work surface and roll out the chilled dough to a 40 x 30cm rectangle, with a long edge closest to you.

8. Spread the cold chocolate date mixture over the dough, leaving a 1cm border all around.

9. Starting from the long edge closest to you, roll up the dough into a tight spiral, with the seam underneath.

10. Trim about 2cm off each end to neaten, then turn the roll through 90° clockwise so that a short end is closest to you. Using a large, sharp knife or a pizza cutter, slice lengthways, down through the middle of the dough, cutting it into 2 long pieces.

11. With the cut-sides facing upwards, gently press the top end of each half together to seal, then lift the right half over the left half, followed by the left half over the right half. Repeat, twisting the dough to make a two-stranded plait, then gently press the bottom ends together to seal.

12. Carefully lift the loaf into the lined tin and sprinkle over the hazelnuts. Cover with a clean tea towel. Leave at room temperature for about 2 hours, until doubled in size.

13. Fifteen minutes before the end of the proving time, heat the oven to 190°C/170°C fan/375°F/Gas 5.

14. When the babka has proved, bake it for 15 minutes, then reduce the oven temperature to 170°C/150°C fan/325°F/Gas 3 and cook for a further 25–30 minutes, until a skewer inserted into the centre comes out clean.

15. When the babka is ready, transfer it in the tin to a wire rack. Brush the date syrup over the hot babka, then leave in the tin until warm enough to handle. Turn out onto the wire rack and serve warm or at room temperature.