To make the dough: In the bowl of a stand mixer fitted with a dough hook, combine 5 cups flour, salt and yeast. Mix on low speed until evenly distributed. (If not using a mixer, whisk together)
In a small saucepan on the stovetop heat pineapple juice, milk, 6 Tbsp butter and honey. Stir until the butter is melted and warm and reaches 120°-130°F. (It needs to be warm since it's added to the dry ingredients and not directly to the yeast)
Add to the dry mixture, mix using a large spoon or non stick silicone spatula.
Add egg, vanilla, vinegar and reserved 1/2 cup flour. Mix well until the dough has a "shaggy" appearance.
Knead for 8-10 minutes (using the mixer or by hand) until the dough is smooth and elastic.
Divide into 15 even portions, roll and place into a buttered 13 x 9 inch baking pan. Cover and let rise for 1-1 1/2 hours or until doubled.
To bake: Preheat oven to 375°F. Move oven rack to lower third position. Uncover rolls. Brush tops evenly with beaten egg wash. Bake for 20-25 minutes or until golden.
Meanwhile, place reserved 2 Tbsp butter with 2 Tbsp honey in a small microwave safe bowl. Heat for 20 seconds or just until melted and brushable.
Once rolls are baked, brush tops with honey butter and serve warm. (It's fine to let the rolls cool in the pan.)