Preheat your oven to 425°F (220°C). This ensures your biscuits bake evenly and rise beautifully.
In a large mixing bowl, combine the all-purpose flour, baking powder, granulated sugar, and salt. Use a whisk to mix thoroughly, ensuring all the dry ingredients are well incorporated.
Take your very cold butter and cut it into small cubes. Add the butter to the dry mixture. Using a pastry cutter or a fork, cut the butter into the flour until the mixture resembles coarse crumbs.
Make a well in the center of your flour mixture and pour in the buttermilk. Stir gently with a spatula or wooden spoon until just combined. Be careful not to overmix; a few lumps are perfectly fine!
On a lightly floured surface, turn out your biscuit dough. Gently knead it a few times until it comes together. Pat it into a rectangle about 1 inch thick for the best height when baking.
Using a floured biscuit cutter or a glass, cut out your biscuits. Press straight down without twisting to ensure they rise properly. Place the biscuits on a baking sheet lined with parchment paper, leaving some space between each.
Bake the biscuits in your preheated oven for 12-15 minutes, or until golden brown on top. If you'd like, brush the tops with melted salted butter for an extra touch of flavor.
Once baked, remove your biscuits from the oven and let them cool slightly before serving. Enjoy warm with your favorite toppings!