Preheat the oven to 425°F.
Place the flour, sugar, salt, and baking powder in a bowl. Stir thoroughly to combine.
Mash in the butter using your fingertips or a fork until the mixture is crumbly.
Pour in the milk, and stir to combine. (Use more if needed if the dough is too dry)
The dough should be soft. Place it on a lightly-floured surface.
Knead gently 8-10 times.
Roll or form the dough with your hands to 3/4 inches thick.
Use a round cookie cutter or invert a drinking glass to cut the dough into portions.
Line a baking sheet with parchment paper and lightly grease with non-stick spray. Place the biscuits on the baking sheet (close together for soft sides, or further apart for crisp sides).
Bake for about 12-15 minutes, or until a toothpick inserted into the center comes out clean. (Optional: Brush biscuits with milk before baking to produce a pretty brown top).
Allow to cool for 5 minutes before serving.