When ready, line or grease two large baking trays and pre-heat the oven to 190°C / 375℉.
Roll out the dough into a large rectangle shape (aim for about 45cm x 55cm as a rough guide).
Melt the butter and then brush it all over the dough.
Sprinkle your raisins over the top (leaving about ½ inch all the way round the edge), and then sprinkle over the zest.
With the shorter side in front of you carefully roll the dough, making sure you pull it tight as you go.
Using a sharp knife, cut the dough into thin slices (you should get 14-18 buns, depending on how big they are).
Pinch any edges together and use your hands to shape them into circles (they will already be round, but might need a little more shaping).
Place them on the baking tray with plenty of space between.
Bake for around 10-14 minutes, just until golden. Do not overbake - they are ready when the bottoms sound hollow when tapped. Too much cooking will result in dry buns.
Remove them from the oven, pop onto a wire rack, and allow to cool completely.