In a small microwave-safe bowl, heat the milk in 30-second intervals until it reaches 110°F, or feels warm to the touch. Pour the warm milk into the bowl of a stand mixer with the dough hook attached.
Add the yeast and 1 tablespoon of sugar to the milk and whisk together. Let it rest for about 5 minutes, or until the mixture becomes foamy.
Once foamy, add the egg, salt, 4 tablespoons of butter, and the remaining 1 tablespoon of sugar. Beat the mixture on medium speed for about 30 seconds until well combined.
Add 1 cup of flour and continue beating on medium speed for another 30 seconds until everything is incorporated. Scrape down the sides of the bowl as needed.
Add the remaining 2 1/4 cups of flour and beat on medium speed for about 1 minute, until the dough starts to come together and pulls away from the sides of the bowl. Continue beating for another 3 minutes until the dough becomes smooth and elastic.
Lightly grease a large bowl with oil. Place the dough into the bowl, turning it to coat with the oil. Cover the bowl with plastic wrap or a clean kitchen towel, and let the dough rise in a warm place for about 1 hour, or until doubled in size.
Grease a 13x9-inch baking pan with oil or cooking spray. Punch down the dough to release air. Divide it into 12 equal pieces (about 70 grams each), shaping each piece into a smooth ball. Arrange the dough balls in the prepared pan.
Cover the pan with plastic wrap or a towel and allow the dough to rise in a warm place for about 1 hour, until puffed up.
Preheat your oven to 350°F and arrange a rack in the lower third of the oven. Bake the rolls for 25 to 30 minutes, rotating the pan halfway through. If the rolls brown too quickly, cover them with foil.
Once golden brown, remove the rolls from the oven and brush them with the remaining 2 tablespoons of melted butter. Sprinkle with sea salt before serving.