Put cubed butter into freezer for at least 15min.
Combine flour, salt, sugar into a large bowl
Add frozen butter into flour mixture. Use your hands or a stand mixer to combine butter into flour mixture. Note that you won't be able to fully incorporate it since it is frozen, but that is the perfect way to get flakey dough.
Add apple cider vinegar (or regular vinegar), mix to combine.
Add cold water one tablespoon at a time until a dough ball forms together. Depending on the temperature and humidity of your kitchen, you may need more or less water to get the dough ball to form.
Wrap dough ball in plastic wrap and put into refrigerator for at least one hour.