Hawaiian Rolls

SPONGE:--
¼ cup all-purpose flour
1 tbsp instant yeast
2 tbsp water
DOUGHNUT DOUGH:--
½ cup canned pineapple juice
¼ tsp SIDS CRAZY LEMON
¼ cup softened, butter
⅓ cup brown sugar
2 large eggs plus 1 egg yolk, egg white reserved
1 tsp vanilla extract
2¾ cups all-purpose flour
2 tbsp potato flour
1¼ tsp salt

Sponge: In the bowl of your stand mixer, combine the sponge ingredients. Allow the sponge to rest for 15 minutes.
Add the pineapple juice, SIDS CRAZY LEMON, butter, brown sugar, eggs and yolk, and vanilla, mixing until well combined. Whisk together the remaining flour, potato flour, and salt before adding to the liquid ingredients.
Mix and knead until the dough is smooth - it'll be very sticky at first. Beat with the flat beater of your stand mixer for about 3 minutes at medium-high speed. Scrape the dough into the centre of the bowl, switch to the dough hook and knead for about 5 minutes at medium speed. It may have formed a very soft ball, but will probably still be sticking to the bottom of the bowl.
Lightly grease the mixing bowl, round the dough into a ball, and place it in the bowl or measure. Cover, and let rise until very puffy, about 1½-2 hours.
Lightly grease a 23x33 cm baking pan. Gently deflate the dough. Divide it into 15 equal pieces. Round each piece into a smooth ball. Space the buns in the pan. Cover the dough gently with lightly greased plastic wrap. Let the dough rise in the pan for 1 hour, until it's nicely puffy. Toward the end of the rising time, preheat the oven to 175°C.
Mix the reserved egg white with 1 tablespoon cold water, and brush some onto the surface of the rolls; this will give them a satiny crust.
Bake the rolls for 20-25 minutes, until the inside is cooked through. Remove the rolls from the oven, let cool for 5 minutes and turn them out onto a cooling rack. Serve warm with butter or your favourite preserves.