In a small bowl, combine the warm milk and yeast. Let it sit for about 5-10 minutes until it becomes frothy. This step awakens the yeast, ensuring a better rise in your rolls.

In a large mixing bowl, whisk together 3½ cups of flour, sugar, and salt. This creates an even base to integrate the wet ingredients smoothly.

Once the yeast mixture is frothy, add it to the dry ingredients along with the egg, butter, and optional vanilla and cinnamon. Mix until cohesive.

Turn the dough onto a floured surface and knead for about 7-10 minutes, incorporating more flour as needed. The dough should be smooth and elastic.

Place the dough in a greased bowl, cover it with a damp cloth, and let it rise in a warm place for at least an hour. It should double in size.

After the dough has risen, punch it down. Divide it into equal pieces, rolling each into a ball. Place the balls onto a greased baking sheet, leaving space between each.

Cover the shaped rolls and let them rise again for about 30 minutes. This final rise is key to achieving that soft texture.

Preheat the oven to 350°F (175°C). Bake the rolls for 15-20 minutes or until golden brown. Brush with melted butter right after they come out of the oven.