Make the dough: In a large stand mixer bowl with a dough hook attachment, mix both flours, yeast, salt and sugar on a low setting. While the mixer is still running, add the melted butter, oil, egg and vanilla followed by the warm milk.
Once a dough forms, increase the speed to medium and knead for 5 minutes with the dough hook. At this point, the dough will be quite sticky but don't be tempted to add more flour yet.
Flour a surface and using a wooden spoon, scrape the dough onto the floured surface. Sprinkle a tablespoon of flour onto the dough to make the outside less sticky then shape the dough into a ball shape.
First rise: Lightly grease a large bowl and place the dough inside the bowl then cover with a tea towel. Allow to rise in a draft free area for 2 hours or until the dough has doubled in size.
Prepare the filling: In a small bowl, mix together the raspberries, sugar and cornflour then set aside.
Assemble the rolls: On a floured surface, roll the dough into a rectangle with a width around about 10 inch/25cm. Spread the raspberry mixture evenly over the dough. Roll up tightly from the short side then cut off both ends if they are not even and cut into 9 even rolls. This part can be slightly messy as the raspberries sauce may leak out in places.
Second rise: Arrange in a greased 9 x 9 inch (23 x 23 cm) tin, cover and allow to rise again for 1 hour until puffy.
Bake: Preheat oven to gas mark 4/350oF/180oC/160oC fan and bake for 28 - 30 minutes until lightly browned.
Make the icing: Whisk the icing ingredients together until smooth and spread on top of the warm rolls. Cover with foil until you’re ready to serve.