Grate frozen butter on large holes of box grater.

Add flour, salt, sugar, baking powder, and baking soda to a bowl and whisk together. Add frozen grated butter then use your fingers to crumble butter fakes into the flour to create a gravely texture. Work quickly to keep from melting the butter.

Drizzle in buttermilk while stirring the mixture. Flip the dough mix out onto a well floured work surface.

Press the powdery mess of dough into a rough rectangle. Use a rolling pin to roll dough out into an 18"/45cm long, 6-7"/17cm wide rectangle.

Now fold the dough - fold top third down over the middle third, then fold bottom (unfolded dough) up over the now folded 2 layers.

Rotate entire folded mass 90 degrees and use rolling pin to roll out into an 18"/45cm long rectangle again. Fold again as you did the first time.

Rotate 90 degrees again and flip to the back side. Use rolling pin to roll into an 18"/45cm long rectangle a third time. Fold again.

Rotate 90 degrees, roll, rotate 90 and roll. In total, you're rolling and folding 5 times.

After the fifth fold, flip dough so the bottom side is facing up again and use the rolling pin to pound and flatten the dough just a bit.

Place on a tray, cover with a towel, and refrigerate for about 10 minutes to firm up the butter and relax gluten.

Place the now cooled dough onto a floured worksurface and slowly roll out into a 10"x10" (25cm) square.

Use a floured knife or bench scraper to cut dough into 9 even squares.

Transfer those squares to a parchment lined sheet tray.

Preheat oven and freeze the cut biscuit dough for 20 minutes.

After removing dough from freezer, brush tops of buscuits with melted butter then bake at 400F/205C for 20-24 minutes, rotating the tray halfway through baking.