In a large mixing bowl, combine 1 cup of room temperature whole milk, 2 tablespoons of granulated sugar, and 1 teaspoon of fine sea salt. Whisk together until the sugar is dissolved. Add in the ¾ cup of active sourdough starter and the melted 2 tablespoons of unsalted butter. Mix until everything is well combined.
Gradually add the 3 cups of bread flour (or all-purpose flour) to the mixture. Stir with a rubber spatula until a shaggy dough forms.
Transfer the dough onto a lightly floured surface and knead for about 8-10 minutes until the dough is smooth and elastic.
Place the kneaded dough in a lightly greased bowl, cover it with a kitchen towel, and let it rise in a warm place for about 1-2 hours, or until it has doubled in size.
Once the dough has risen, punch it down to release the air. Turn it out onto a lightly floured surface and divide it into equal pieces, about 12-15. Roll each piece into a ball and place them in a greased 9x13 inch baking pan.
Cover the pan with a kitchen towel and let the rolls rise again for about 30-45 minutes, or until they are puffy and touching each other.
Preheat your oven to 375°F (190°C). Once the rolls have risen, brush the tops with melted salted butter. Bake in the preheated oven for 20-25 minutes or until they are golden brown.
Remove the rolls from the oven and brush with additional melted butter if desired. Let them cool in the pan for a few minutes before transferring them to a wire rack. Serve warm.