01 - Combine warm milk, sugar, and active dry yeast in a large bowl. Let sit for 5 minutes until foamy.
02 - Add flour, salt, softened butter, and egg to the yeast mixture. Mix until a cohesive dough forms.
03 - Transfer dough onto a lightly floured surface and knead for 8 to 10 minutes until smooth and elastic.
04 - Place the dough in a lightly oiled bowl, cover, and let rise in a warm spot for 1 hour, or until doubled in volume.
05 - Punch down the dough, then divide it into 8 equal portions. Shape each portion into a tight ball and arrange on a parchment-lined baking sheet, leaving space between rolls.
06 - Cover the rolls and allow them to rise again for 20 to 30 minutes until puffy.
07 - Preheat oven to 375°F (190°C).
08 - Brush the rolls with half of the melted butter.
09 - Bake for 18 to 20 minutes until golden brown.
10 - Remove rolls from oven, immediately brush with remaining melted butter, and sprinkle with sea salt flakes if desired. Serve warm.