For the filling
1. Mix the butter, brown sugar, cocoa powder and cinnamon together in a medium bowl to form a paste, then leave aside.
2. When the dough has fully proved tip it out of the bowl and punch it down then divide it into 2 equal parts. Using a rolling pin, roll each piece into a rectangle about 11-inches in width by 17-inches in length.
3. Spread half the chocolate cinnamon filling and half the dark chocolate chips over the top leaving ½-inch border all the way around, then roll up the dough horizontally into a log. Wrap each piece in parchment paper and transfer it to a baking sheet.
4. Repeat with remaining dough and filling then transfer loaves to fridge to chill for 15 minutes.
5. While it chills, grease a 2lbs loaf tin with butter.
To assemble
1. Place one chilled log onto a large cutting board and remove baking paper. Cut the log in half lengthwise and lay them next to each other cut sides up so you can see all the chocolate lines on the inside.
2. Lift one half over the other and twist each around the other, then transfer the twist as best as you can into the prepared loaf tin.
3. Repeat with the other log and cover tin with a tea towel to prove again for 1 hour.
4. Preheat the oven to 180C, then place the loaves in the oven and bake on the middle rack of your oven for 25 – 30 minutes.
5. Remove them from oven and brush maple syrup generously over both loaves whilst they're still warm.
6. Leave for 15 minutes then turn them out onto a wire rack to cool.
Recipe and image credit: @mykitchendrawer in collaboration with Smeg and Mason Cash