Preheat oven to 450 degrees. Lightly grease a heavy bottom baking sheet with canola oil.
Combine your dry ingredients in a large mixing bowl.
Cut the fat into the flour with your fingers or a pastry cutter until it resembles course meal and there are no pieces of fat bigger than a pea.
Stir in the buttermilk until just combined.
Let this sit out to proof for 20 minutes.
Turn the dough out onto a well floured work surface and sprinkle the top lightly with flour.
Form dough into a rectangle with the narrow side facing you, about 1 inch thick.
Fold the dough in half, folding the far side of the dough toward you.
Turn the dough clockwise, gently pat back out in a rectangle and repeat this three more times, careful not to pat out the air pockets created by the folding, as these are essential to a light, tall, flaky biscuit.
After the forth fold, shape your dough into a nice circle and make sure your work surface has enough flour to roll the dough out.
Using a rolling pin gently "bounce" your dough out from the middle until about 2 inches thick, sheen with a little flour, just to smooth dough, and continue to roll out until 3/4 inch thick.
Using a floured biscuit cutter of your choice, cut the biscuits out starting from the sides.
Do not twist your biscuit cutter as this will seal the sides of the biscuits and prevent rising.
Gently place biscuits onto your greased sheet pan.
Let proof again once cut for another 20 minutes.
Depending on the size of your biscuits bake for 8-12 minutes.
Check them often the first time, baking until just golden.
If your biscuits are done on the outside and doughy on the inside, your oven is too hot.
Brush tops with butter if desired.
*Cool biscuits completely before storing in an air tight container. To reheat biscuits, lightly wet tops and microwave or put in the oven. Reheating in the oven will make them dryer.