Preheat the oven to 400 degrees F. While the oven is heating up, take your stick of butter and cut it up into smaller pea-sized pieces. Place the small pieces of butter into a medium bowl and place back in the refrigerator (to stay very cold) until you're ready to add them to the flour mix.
Combine: In a large mixing bowl combine all the dry ingredients. Add the cold butter pieces into the dry ingredients and begin to combine with a fork or pastry cutter. As you combine, the flour begins to incorporate with the butter, which will melt as it cooks for the fluffy texture (and buttery flavor). Then add the remaining wet ingredients (buttermilk). Stir with a wood spoon or sturdy spatula until combined.
Bake: Form biscuits using your ice cream scoop and place biscuits into the cast iron pan. You should get 9 biscuits. Place into the oven and bake for 25 minutes or until the tops of the biscuits start to turn slightly golden. Then remove from the oven and serve warm.
Optional: As soon as you remove the biscuits from the oven, melt 2 tablespoons of unsalted butter (we use the microwave) in a small bowl and then brush the melted butter onto the tops of the biscuits. Then sprinkle some kosher salt or finishing flake salt onto the biscuits.