Preheat oven to 400˚F. 

Using a box grater, grate the butter using the largest holes. Place the grated butter in the freezer while you mix together the dry ingredients. 

In a large mixing bowl, whisk together the flour, baking powder, baking soda, salt and sugar. Add the cold butter. Gently toss the butter with your hands to coat with flour, trying not to break up the pieces. Make sure the mixture feels cold; if it doesn’t, freeze the mixture for a few minutes. 

Working quickly so the butter doesn’t soften, make a well in the center of the dry mixture. Slowly pour the buttermilk into the well, using your other hand to mix the buttermilk into the dry mixture. Continue mixing until the buttermilk is incorporated and a dough starts to form. If it seems dry, add a splash of buttermilk. 

Dump the dough out onto a floured surface. Sprinkle some flour over top and press the dough gently to form an 8-inch square. Cut into 16 squares to make roughly 2-inch square biscuits. Arrange the squares onto a large sheet tray. Bake until risen and and the biscuits begin to brown on top, about 20 minutes.