1. 1. Combine Wet Ingredients: In a large mixing bowl, whisk together the active sourdough starter, warm milk, granulated sugar, salt, lightly beaten egg, and 3 tablespoons of melted and cooled butter. Ensure everything is well combined and the sugar has dissolved. The mixture should look slightly milky and uniform.

2. 2. Add Dry Ingredients: In a separate bowl, whisk together the all-purpose flour, baking powder, and baking soda. Gradually add the dry ingredients to the wet ingredients, mixing with a wooden spoon or your hands until a shaggy dough forms. Don’t overmix at this stage; just combine until no dry streaks remain.

3. 3. Knead the Dough: Turn the dough out onto a lightly floured surface. Knead for about 5-7 minutes until the dough is smooth and elastic. It should be soft and slightly tacky, but not sticky. If it’s too sticky, add a tiny bit more flour, one tablespoon at a time.

4. 4. First Rise: Lightly grease a clean bowl with oil. Place the dough in the bowl, turning it once to coat the top. Cover the bowl with plastic wrap or a clean kitchen towel and let it rise in a warm place for 1.5 to 2 hours, or until doubled in size. The dough should look puffy and feel airy.

5. 5. Shape the Rolls: Gently punch down the risen dough to release the air. Turn it out onto a lightly floured surface and divide it into 12 equal pieces. Roll each piece into a smooth ball. Arrange the dough balls in a greased 9×13-inch baking dish, leaving a small space between each roll.

6. 6. Second Rise: Cover the baking dish loosely with plastic wrap or a clean kitchen towel and let the rolls rise again in a warm place for another 30-45 minutes, or until they look visibly puffy and have nearly doubled in size. This second rise is crucial for light, airy rolls.

7. 7. Bake the Rolls: Preheat your oven to 375 F (190 C) during the last 15 minutes of the second rise. Bake the rolls for 18-22 minutes, or until they are golden brown on top and cooked through. The internal temperature should reach around 200-205 F (93-96 C) if you use a thermometer.

8. 8. Finish and Serve: Once baked, remove the rolls from the oven. Immediately brush the tops with the remaining 2 tablespoons of melted butter. This adds flavor and gives them a beautiful sheen. Let them cool in the pan for a few minutes before serving warm.