Heat your oven to 450°F (230°C) before using it. In a big bowl, mix the flour, baking powder, and salt using a whisk. Use a pastry cutter or your fingers to mix the butter until the mixture looks like rough sand. Create a hole in the middle of the mixture and add the buttermilk. Mix gently until the dough forms.
Place the dough on a surface with a little flour and knead it softly a few times. Flatten the dough into a rectangle that is 1 inch thick. Use a 2-inch round cutter to make biscuits and put them on a baking tray. Collect the leftover dough and flatten it out again. Cut more biscuits until all the dough is used.
Cook the cookies in the oven for 12-15 minutes, or until they turn golden brown. Serve it hot. Have fun!