PREPARE THE DOUGH:
Line a quarter sheet pan with parchment paper and dust generously with flour.
On the small opening of a cheese grater, shred the asiago cheese. Set aside.
Finely chop the rosemary and set aside.
In a large bowl, combine the flour, baking powder, and salt.
Add the butter and combine until the butter is broken down into pea sized bits.
Add the cheese and rosemary, combine.
Add the buttermilk and mix just until the dough starts to come together.
Place the dough on the prepared sheet pan and press to fill the pan. Cover and place in the refrigerator for 30 minutes.
FOLDING AND LAYERING THE DOUGH:
Once chilled, roll the dough out on a well-floured surface into a 1/4 inch thick rectangle. Fold into thirds as you would a letter.
Roll the folded dough out and fold again in the same fashion as Step 1.
Place in the refrigerator for 30 minutes if you notice any butter melting or if the dough seems to be getting sticky. If not, move on to Step 4.
Roll out and fold like a letter one last time.
Roll out the final layered dough until 1/2 inch thick.
Cut rounds of dough with a biscuit cutter or a drinking glass, cover, and place in the freezer for 15 minutes.
Preheat your oven to 425ºF while the biscuits chill.
Once chilled, brush the tops of the biscuits with melted butter and sprinkle with a pinch of flakey sea salt. Bake for 14-16 minutes or until the tops have turned golden brown.
Cool for 10 minutes before serving.