In your mixing bowl add All-Purpose Flour (4 tablespoon), Instant Dry Yeast (1 tablespoon) and Water (2 tablespoon). Mix together, cover and let it rest for 15 minutes.
After it has rested add the Pineapple Juice (1/2 cup), Egg (3) (2 whole and one yolk), Brown Sugar (1/3 cup), Unsalted Butter (4 tablespoon), and Vanilla Extract (1 teaspoon), and mix until completely combined.
In another bowl add the All-Purpose Flour (1 cup), Salt (1 1/2 teaspoon) and Corn Starch (2 tablespoon). Turn your mixer off and add the mixture. Continue to mix until smooth.
Switch to a dough hook and add All-Purpose Flour (1 cup). Mix until combined and scrape down the sides.
Add the remaining All-Purpose Flour (1/2 cup) and mix until it starts to pull together as a dough. Stop the mixing and scrape everything down then continue to knead for another 5 minutes.
Remove the dough. It should be sticky but should not stick completely to your hand. Flour your surface and knead the dough a few times. You should be to press on the dough and have it spring back. Place the dough in a bowl, cover and let it rise for about 1 1/2 hours.
Preheat your oven to 375 degrees F (190 degrees C). Spray a 9x13-inch baking dish with baking spray.
Create 16 dough balls about 60 grams each. Sprinkle some flour on your surface. Gather the outside edges and pinch towards the bottom, roll so they have a smooth top and a small crease in the bottom. Place in your baking dish and let it sit for 45 minutes.
Beat the reserved egg white from earlier and brush the tops with it. Bake in your preheated oven for 20-25 minutes.
Remove from the oven and brush with Butter (to taste).