Preheat oven to 450℉.
In a large mixing bowl, whisk together all dry ingredients.
Remove cold butter from fridge and slowly mix with dry ingredients, using your hands. Do not mix so much that butter begins to melt. There should be small bits of solid butter throughout.
Add milk. Knead dough with hands until fully incorporated. Butter should still be visible.
Place dough on a floured surface. Rub flour on rolling pin and roll out biscuit dough until between ¾ to 1 inch thick.
Use a biscuit cutter to cut out biscuits, placing them a few inches apart on a greased baking sheet. Reroll the dough if needed. Work quickly, as the butter should not melt.
Brush melted butter on top of each biscuit. Bake for 10 to 15 minutes, until golden brown. Meanwhile, make the gravy: