Place butter in the freezer for at least 20 minutes.
Preheat oven to 425° F with a rack in the upper third of the oven. Line a baking sheet with parchment paper.
In a large bowl, combine the flour, baking powder, sugar and salt. Whisk together until well combined.
Grate the frozen butter using a box grater. Add the butter to the bowl and mix it into the dry ingredients using your hands or a fork.
Pour the 1 cup milk or buttermilk into the bowl and use a fork to stir until the dough comes together. It is ok if there are a few bits of flour not yet incorporated, but if the dough seems very dry and is not coming together add 1 to 2 tablespoons more milk or buttermilk.
Turn the dough out onto a lightly floured work surface. Pat the dough into a 1½-inch thick rectangle. Fold the dough in half on top of itself and pat it down into another 1½-inch thick rectangle. Repeat the folding process 4 to 6 times. Then press the dough down into a 1-inch thick rectangle.
Use a biscuit cutter (mine measures 2 ¼-inches) to cut out the biscuits, pressing it straight down into the dough without twisting. Once you've cut out as many biscuits as you can, gather the scraps and pat the dough out to 1-inch thickness a second and third time to finish cutting out all of the biscuits. Place them on the prepared baking sheet.
Brush the biscuit tops with milk, buttermilk or cream. Bake for 13 to 16 minutes, until the tops are lightly golden brown.