In a mixing bowl, combine the room temperature butter and beat it until it becomes fluffy.
Next, add the powdered sugar and continue mixing until the mixture is fluffy and noticeably lighter in color.
Gradually incorporate the sifted flour and kosher salt, mixing until just combined.
Transfer the mixture to a buttered pan and press it down gently.
Refrigerate the pan for at least 30 minutes.
Preheat the oven to 300°F (150°C) and bake the biscuits for one hour.
