In a large mixing bowl, combine the milk, pineapple juice, sourdough starter, egg, sugar, honey, and vanilla. Stir until mostly smooth.
Add the bread flour and sea salt. Mix until a shaggy dough forms.
Add the softened butter and knead until fully incorporated. Continue kneading for 8–10 minutes until the dough is smooth, elastic, and slightly tacky.
Cover and let the dough rise at room temperature for 6–8 hours, or until it has increased by about 50–75%.
Perform 2–3 sets of stretch and folds during the first 90 minutes if desired for additional strength.
Turn the dough onto a lightly floured surface.
Divide into 15 equal pieces (about 75–78 grams each).
Shape each into a smooth ball.
Arrange the rolls in a greased 9×13-inch baking pan in a 3×5 pattern.
Cover and proof 2–4 hours, or until very puffy.
For enhanced flavor, refrigerate overnight after shaping. The next day, allow the rolls to finish proofing before baking.
Preheat oven to 350°F (175°C).
Bake for 22–28 minutes, or until golden brown and the internal temperature reaches about 190°F.
Brush immediately with melted butter.
Allow to cool for 10–15 minutes before serving.