In a saucepan, warm the milk and sugar, on medium low heat, until it comes to a low simmer. Stir constantly to keep the milk from burning. You want the sugar to dissolve and the milk to just barely start to simmer. Remove it from the heat and carefully add the 4 Tablespoons of butter. Stir until the butter is completely melted. Set aside and let it cool until it comes to around 100°F/37°C. It will be warm, but not so hot that it kills the yeast.

To the bowl of a stand mixer, add the cooled down (but warm) milk mixture, warm water, yeast, eggs, potato flakes and salt. Add half of the flour. Mix on low, using the dough hook attachment. Allow all the ingredients to come together until smooth, about 2 minutes. Gradually add the rest of the flour, about 1/2 cup at a time. Let the flour fully incorporate between additions. Knead on low speed for 5-7 minutes, until the dough comes together in one smooth mass. Dough should clean the sides of the bowl and concentrate around the dough hook. Add 1-2 Tablespoons additional flour, as needed, if dough is excessively wet or sticky.

Place the dough in a large bowl, sprayed with nonstick spray. Turn the dough so that all sides are coated with the spray. Cover the dough and let it rise in a warm place in your kitchen until it doubles in size, about 90 minutes to 2 hours.

After the dough has risen, turn it out onto a lightly floured work surface. Divide the dough in half, as this recipe makes two dozen rolls.

Working with one half of the dough at a time, roll the dough to a rectangle, about 8x12-inches. Be sure to lightly flour work surface to prevent dough from sticking. Melt 3 Tablespoons butter and brush half of it over the surface of the dough.

With a pizza cutter, cut the rectangle in half lengthwise - this creates two rectangles, 4x12-inches in size.

Fold over each piece of dough lengthwise, stopping about 1/4-inch before the bottom edge. You'll now have two long pieces of folded dough that are about 2 1/4-inches by 12 inches.

Cut each rectangle into 6 equal pieces. This will give you 12 total folded rolls, about 2 1/4-inches by 2-inches.

Flip each roll over so that the longer side is on top. Place on a baking sheet either lined with parchment or prepared with nonstick spray. Roll out and shape the second dozen of rolls. You can fit all 24 rolls on one half-size baking sheet (18x13-inches) if you arrange them in 6 rows of 4. 

Cover the rolls and let them rise until puffy, about 45 minutes to 1 hour. Towards the end of the final rise, preheat oven to 350°F/176°C.

Bake for 18-22 minutes, until golden. Brush with melted butter right out of the oven.

Let rolls cool in the pan 10 minutes before serving.