Preheat oven to 350 degrees.
Grate frozen butter, using a box grater, onto a baking sheet lightly coated with flour, and then toss lightly with flour to coat.
Whisk together flour, sugar, baking powder, and salt in a large mixing bowl. Add in butter and fold into flour, mixing with your hands until flour resembles sand. Add buttermilk and mix with your hands until dough comes together into a large ball (it should be soft and sticky).
Scoop biscuits, using a 4-oz ice cream scoop or 1/2 cup measuring cup sprayed with nonstick cooking spray, onto the sheet pan, leaving 1 inch between each biscuit. Bake for 10 minutes then turn and rotate pan and bake another 10-15 minutes. Check for color and doneness. The biscuits should be golden brown, crispy around the edges, and cooked in the middle.