Preheat your oven to 450°F (232°C). A hot oven is crucial for achieving those tall and flaky biscuits.
In a large mixing bowl, whisk together the all-purpose flour, baking powder, sugar, and salt until well combined.
Add the cold unsalted butter cubes to the dry mixture. Using a pastry cutter or a fork, cut the butter into the flour mixture until it resembles coarse crumbs.
Pour in the cold buttermilk and stir gently with a spatula until the dough just comes together. Be careful not to overmix; it’s okay if there are some lumps.
Turn the dough out onto a lightly floured surface. Gently pat it into a rectangle about 1-inch thick. Fold the dough over itself three times, turning it 90 degrees each time.
Using a floured biscuit cutter, cut out the biscuits. Place them on a baking sheet lined with parchment paper, making sure they are touching for extra rise.
Before baking, brush the tops of the biscuits with melted unsalted butter for added flavor and a beautiful golden color.
Bake the biscuits in the preheated oven for 12-15 minutes, or until they are golden brown on top.
Remove the biscuits from the oven and let them cool slightly before serving. They are best enjoyed warm, straight from the oven.