To start, set the oven on high at 425F. It is best to bake the biscuits in a Cast-Iron Skillet. Placing them in the skillet keeps them round and helps them bake better. If you do not have one, place the biscuits on a baking sheet and do not leave a gap between them.
Sift all the dry ingredients into a large bowl. Cube the butter into small pieces and add them to the dry ingredients. Use clean hands to press the cold butter into the flour mixture. We do not try to melt or fully incorporate the butter into the flour. Stop when all the butter is pressed into little shards, and the mixture looks like wet sand.
Make a well in the center of the mixture, pour the buttermilk and vanilla extract into it, and fold the mixture together.
¾ cup Buttermilk, 1 teaspoon Vanilla extract
Dump the mixture on a clean and lightly floured surface and gently knead it a few times until it is not powdery anymore.
Make a rectangle out of the dough about 1 inch thick. Threefold the dough, tap it down into a rectangle again and repeat these steps three times. Flour your hands as needed. The final dough should be ½ inch thick. Add 2 to 3 tablespoons of buttermilk if the dough is too dry.
Cut the dough using a Three-inch Round Cookie Cutter. Place the cookies in the skillet or baking sheet, not leaving a gap between them. Bake for 10-12 minutes until the top is golden. Immediately after removing them from the oven, brush them with melted butter.