Heat the milk and butter in a small saucepan. (Do not over heat, otherwise the yeast will break: only lukewarm)
Add Butter Mixture to the flour mixture and knead into a smooth dough.
The dough should be detached from the bowl.
Cover and let rest in a warm place for 60 minutes. Roll out the dough on a floured surface to a rectangle.
Make sure the dough is smooth and evenly thick.
Spread the softened butter all over the dough. In a small bowl, toss the brown sugar, cinnamon and apples together until combined and then sprinkle evenly over the dough.
Roll up and cut into equal rolls.
Arrange them in the prepared baking pan. Cover the rolls very tightly with a kitchen towel.
Allow rolls to rise in a warm environment again for about 60 minutes or until doubled in size.
Preheat the oven to 180°C. Bake rolls for about 25 - 30 minutes until they are golden brown. About halfway through the bake time, I like to cover the rolls loosely with aluminum foil so the tops don't brown too much. Remove pan from the oven and allow to cool on a wire rack for 5 minutes.
Whisk all of the icing ingredients together and drizzle over warm rolls. Serve.
Overnight instructions: To prepare the night before serving, prepare the rolls through step 10. Cover the rolls tightly and refrigerate for 8-10 hours. The next morning, remove from the refrigerator and allow to rise on the counter for 1-2 hours before continuing with step 11.