Sift the flour into a large bowl, and add the sugar and yeast. Mix it around a bit with a spoon so its all combined.
Rub the butter in with your fingers until it resembles breadcrumbs - or, add the ingredients to a food processor and whizz it up to get the same affect.
Add the lemon zest to the mixture.
Heat the milk gently until warm - make sure its not too hot. It should be just about steaming, but definitely nowhere near boiling!
Add the milk and egg into the dough, and knead the mixture for about 7-10 minutes.
I use my Kitchenaid with the dough hook so it takes about 6-7 minutes, and I don't get messy! The dough will be done when you press it in, and it springs back. It should also not be sticky anymore.
Move the kneaded dough to a lightly oiled bowl (a large bowl so it has room to grow) and leave it in a warm place for 1-2 hours, or until doubled in size. If its a cold day, it can take longer.
Once the dough has risen, remove it from the bowl, and roll out onto a lightly floured work surface.
Roll the dough to about 50x30cm (a large rectangle)
Gently brush the surface of the dough with the melted butter - sprinkle over the sugar, and then sprinkle over the raspberries and white chocolate chips.
Roll the dough from long end to long end (so you have a longer sausage compared to a short stubby sausage) carefully but tightly.
Cut this carefully into 12 equal sized pieces, and put into a rectangular oven dish (mine was 12x9" in size).
Cover again, and leave to rise for an hour. Towards the end of the hour, turn the oven on to 180C Fan, and when its fully risen, bake in the oven for 20-25 minutes.
Once baked, leave to cool.
Notes
I used frozen raspberries as they produce a delicious raspberry like sauce that makes the rolls gooey.