Place a rack in the center of your oven and preheat to 375°F. Line 2 large baking sheets with parchment paper. Set aside.
In a large bowl, combine flour, salt, and baking powder. Whisk to incorporate.
Add cold, cubed butter to the dry ingredients. Cut the butter into the flour mix until the pieces of butter are slightly larger than the size of a pea. Add the buttermilk and mix until everything just comes together into a rough dough.
Turn the dough onto a lightly floured work surface. Press the dough down to flatten it to about 1/2 an inch thick, then fold the dough in half. Repeat the pressing and folding process 3 to 4 more times to build flaky layers into the dough. Try to work as quickly as possible to avoid having the butter warm up too much.
Roll the dough out until it's about 1/2 an inch thick. Using a 2-1/2 inch, round biscuit cutter, cut the biscuits. Gather up the scrap pieces of dough and repeat the rolling and cutting process until all the dough is used up.
Arrange the cut biscuits on your baking sheet, leaving a bit of room in between for them to expand in the oven. Bake in a preheated 375°F oven for 15 to 20 minutes, or until golden brown on top. Biscuits are best served warm.