Step 1

Combine the yeast, milk, water and 1 tsp of the sugar in a small bowl. Set aside for 5 mins or until frothy.

Step 2

Combine flour, salt, cinnamon and remaining sugar in a large bowl. Make a well in the centre. Add the yeast mixture, eggs and egg yolks and stir to combine. Turn onto a lightly floured surface and knead until just smooth. Add 1 piece of butter and knead until well combined. Continue adding butter, 1 piece at a time, kneading well after each addition. Knead the dough for a further 5 mins or until dough is very smooth and elastic. Place in a lightly greased bowl. Cover with plastic wrap. Place in the fridge for 6 hours or until the dough doubles in size.

Step 3

To make the chocolate filling, use an electric mixer to beat butter and sugar in a bowl until smooth. Add chocolate, cocoa powder and cinnamon. Beat to combine. Place in fridge for 5-10 mins or until the mixture is spreadable.

Step 4

Preheat oven to 180°C. Grease two 10cm x 24cm loaf pans and line the bases and sides with baking paper. Line a baking tray with baking paper. Turn the dough onto a lightly floured surface. Divide into 2 even portions. Roll 1 portion out on a lightly floured surface to a 30cm x 40cm rectangle. Spread evenly with half the chocolate mixture. Starting from 1 long end, roll the dough to form a log. Place on the lined tray. Repeat with the remaining dough and filling. Chill for 5 mins or until firm.

Step 5

Place 1 log on a clean work surface. Use a large sharp knife to cut the dough in half lengthways to expose the layers. Carefully twist the 2 halves together to create a loaf. Place in 1 prepared pan. Repeat with the remaining dough and pan. Loosely cover with plastic wrap and place in a warm, draught-free place for 30 mins or until the dough rises slightly.

Step 6

Bake the loaves for 35-40 mins or until a skewer inserted in the centres comes out clean.

Step 7

To make the sugar syrup, combine the sugar, ½ cup (125ml) water and vanilla in a saucepan over low heat. Cook, stirring, for 2 mins or until sugar completely dissolves. Increase heat to high. Bring to the boil. Cook for 2-3 mins or until the syrup thickens slightly.

Step 8

Pour the syrup evenly over each loaf. Cool in the pans. Cut into slices to serve.