In large bowl combine flour, baking powder, salt, and baking soda. Mix to combine.
Using a box grater, shred 6 tbsp of cold butter (best if frozen, but refrigerated works). Add butter to bowl with flour.
Add buttermilk to the flour bowl, and using a wooden spoon, mix to combine. (try not to use your hands so you don't transfer heat which melts the butter)
Once the dough is starting to come together into a ball, pour it out onto a floured surface and form it into a ball.
Using a dough scraper, cut the ball in half, then place one-half on top of the other, and repeat to do this a total of four times.
Roll the dough to be 1" thick, being careful not to overly press the dough.
Using a round cookie cutter, press straight down into the dough to cut out biscuit rounds and place them on a greased baking sheet.
Remaining dough scraps can also be made into biscuits but they won't rise as much.
Preheat oven to 450 degrees.
Place baking sheet into the freezer for 10 minutes to allow butter to re-chill.
Place in oven for 10-12 minutes, until biscuits rise and cook through.