Only use real butter in this recipe. Substitutes like can cause issues with sticky dough etc.
Make sure your surface is well floured before you drop the dough onto it, you can sprinkle a little flour on top before you from it into a circle to roll out. The goal is to keep the dough as soft and unworked as possible.
I usually sprinkle on flour and fold the dough only about 3 times. So, while you can add more flour while working the dough into shape, don't overdo it or your raisin will be less soft and tender.
Do not roll them too thin; never thinner than 1 to 1 1/2 inches. The larger the buns the thicker I tend to cut them.
Make sure you oven is well preheated and use aluminum bakeware when possible. Steel/alloy pans can carry heat too quickly and like they do sometimes with cookies, spread wider on the pan before they get the chance to lift.