Knead soft dough with the flour, yeast, sugar, butter and milk. Cover and allow proving until double in bulk. Roll out the bun dough into a large square. Spread with custard and cinnamon. Take a milk chocolate bar and break into small chips. Roll up like a Swiss roll and cut into slices across the roll 3cm wide. Place on a greased baking tray, cover and allow to rise till double in size. Bake in a hot oven temp 200°c for approximately 15 minutes. Meanwhile prepare a bun wash, boil together the water and sugar until the consistency of a thick syrup. Brush the buns liberally with the bun wash as soon as cooked.