Prepare the dough by mixing flour, sugar, salt, and yeast. Add warm milk, melted butter, and egg until a soft dough forms.
Let the dough rise in a greased bowl for about 2 hours until doubled in size.
Roll the dough into a rectangle, spread softened butter, and sprinkle cinnamon. Mix filling ingredients together and distribute evenly.
Roll tightly and cut into 12 rolls. Place in a greased pan and let rise for another hour or overnight in the fridge.
Preheat oven to 350°F and bake for 25-30 minutes until golden brown.
Cool slightly, then top with icing and serve warm.