In a medium mixing bowl, combine flour, baking powder, sugar and salt. Whisk and set aside.Note: For best accuracy, measure flour by weight in grams instead of cups. If you don't have a scale, fluff the flour with a fork in its bag or container, then spoon it into the measuring cup before leveling off with a flat edge.

Grate the butter onto a plate and place into the freezer for 20 minutes.

Add the cold, grated butter to the dry ingredients bowl and mix lightly to coat. Then, make a well in the center and add the cold milk. Let it sit and slowly incorporate the flour and milk until the dough comes together and the liquid is absorbed. The dough will be shaggy and fall apart. That is normal and exactly what you want.

Pour the dough and any dough crumbles onto a clean, well-floured surface. If the dough becomes sticky in some areas, add a bit of flour over the surfaces until it is manageable. Use your hands to gently bring the dough together into a cohesive rectangle.

Pre-heat the oven 425°F. Line a baking sheet with parchment paper and set aside.

Shape into a rectangle, about 9 inches long. Cut into thirds. Stack and press. Rotate and use a rolling pin to reinforce the shape into a larger rectangle again. Repeat the layering and rotating steps 4 times total.

After you've repeated the lamination layering at least 4 times, use a rolling pin to smooth out into a large rectangle., about 9 inches long.

Cut the dough into 8 large square biscuits. Place the biscuits onto the un-greased baking sheet. While the oven is preheating, freeze the baking sheet with the biscuits for at least 15 minutes.

Brush only the tops of the biscuits with egg wash. Bake for 20-25 minutes until the edges and the tops are golden. Note: Make sure the egg wash doesn't fall over the sides. The eggs will seal the layers and limit the height of your lamination during baking.