Stir together the brown sugar and cinnamon and set aside.
Grease a 9x5 loaf pan and line it completely with parchment. I wouldn’t skip the parchment since some of the swirl will leak to the bottom and cause your bread to stick.
Once the dough has proofed, give it a few kneads and pat or roll it out into a 8x15 inch (20x38 cm) rectangle with the short side facing you.
Brush the surface lightly with milk and sprinkle the sugar and cinnamon mixture evenly over it, leaving an edge at the top so the dough can stick to itself once rolled.
Starting with the side closest to you, roll the dough up tightly and pinch the end seam shut.
Place it in the prepared loaf pan. If raisins are poking out of the top, take them out and tuck them into the folds in the side to prevent them burning in the oven. Cover back up with the damp tea towel and let proof a second time until almost doubled in size (about 30 to 60 minutes).
When it’s almost done proofing, preheat your oven to 190°C/375°F. When it’s ready to be baked, brush the top with milk and bake for about 50 minutes or until the internal temperature reaches between 90°C/194°F to 94°C/201°F. If you see that the top is browning too fast, you can cover it loosely with aluminium foil and continue baking.
Let it cool 5-10 minutes in the pan before removing to a wire rack and letting it cool completely before slicing.