Grease and line a large baking sheet.
Mix the lukewarm milk with the yeast and leave to prove for 15 minutes until starting to froth slightly.
Using the k-beater in mixer, mix the flour, currant bread powder, flour booster, salt and sugar. Change k-beater to dough hook and mix in the butter, egg and yeast/milk mixture. Once combined, knead for 10 minutes. Add raisins and knead for another minute, until well combined.
Cover mixer bowl with cling film and leave to rise until doubled in size (approx. half an hour).
Once risen, divide mixture into 16 portions (roughly 65g each). Shape each one into a flat roll and place on prepared baking tin, fairly close together but not touching – 4 rows of 4.
Preheat oven to 200◦C. Cover rolls with cling film and place a plastic tray on top. (This will ensure you get flat rolls, as they will rise out to the side towards each other). Leave in a warm place to rise, until rolls are plump and joining each other (this may take 30-40 minutes).
Remove tray and cling film and spray the risen rolls with water. Place in oven and cook for 20 minutes. Open the oven door and spray the rolls regularly during the cooking time.
Remove from the oven and re-spray with water. Leave for 5 minutes then remove to a cooling rack.