In a stand mixer, combine 2 tablespoons of lukewarm water and the yeast. Mix well and let sit until dissolved for about 5 minutes. (You can also mix and knead by hand.)
Meanwhile, combine milk, butter pieces, sugar, and salt in a medium microwave-safe bowl. Heat in the microwave for a few seconds, and stir. Repeat until the butter melts. If the mixture is over 115℉ (45℃), let it cool so it doesn't kill the yeast and curdle the eggs.
Lightly whisk the eggs and vanilla extract, then add them to the butter mixture. Dump everything into the yeast mixture.
Add the pineapple, and mix on medium-high using a dough hook until well combined.
Then add 3¾ cups of flour and mix the dough for about 8 minutes or until it pulls away from the sides of the bowl. Add as little flour as little as possible to make a soft dough.
Or turn the dough out onto a lightly floured surface and knead by hand for 8-10 minutes.
Place bread dough in a large, greased bowl. Cover loosely with a clean cloth and let it rise in a warm, draft-free place for 1-2 hours or until doubled in size. Punch the dough down.
Divide the dough into 12 equal pieces and shape them into balls. Place them in a greased 12-inch round pan. Or you can make bread by shaping the dough into a log and settling it seam-side down into a greased loaf pan.
Whisk the milk and egg yolk, then brush the rolls or bread with the egg wash. Cover them with a clean kitchen towel and let rise for 2 hours. You can refrigerate for up to 24 hours; they will rise slower and taste amazing.
Preheat the oven to 350℉ (175℃). Bake until the crust is deep golden brown and they sound hollow when tapped (about 20 minutes).
Remove from the pan and let cool. They're absolutely delicious served warm.