Grate Frozen Butter: Place a stick of butter in the freezer for 30 minutes. Grate the frozen butter on the large holes of a box grater into a chilled bowl. Return grated butter to freezer while prepping dry mix.
Whisk Dry Ingredients: In a large mixing bowl, thoroughly whisk together all-purpose flour, baking powder, baking soda, salt, and granulated sugar.
Toss Butter with Flour: Add the frozen grated butter to the flour mixture. Use your fingertips to quickly toss and coat every butter strand in flour until crumbly and pea-sized (work fast so butter stays cold).
Pour Cold Buttermilk: Make a well in the center and pour in ice-cold buttermilk. Stir gently with a rubber spatula just until a shaggy dough begins to form (do not overwork).
Laminate Layers (The Secret!): Turn dough out onto a lightly floured counter. Gently pat into a 1/2-inch rectangle. Fold the dough in thirds like a business letter. Turn 90 degrees, pat down, and fold in thirds again. Repeat this folding process 4 to 5 times to create dozens of distinct laminated flaky layers!
Cut Without Twisting: Pat dough into a 1-inch thick slab. Dip a 2.5-inch round biscuit cutter straight down into flour, then press firmly straight down through the dough—DO NOT TWIST the cutter (twisting seals the edges and prevents the biscuits from rising sky-high). Gather scraps once and cut remaining biscuits.
Bake Touching at 425°F: Arrange biscuits in a greased cast-iron skillet or parchment-lined baking sheet with sides touching each other (touching supports them to climb upward instead of spreading out). Bake at 425°F (220°C) for 15-18 minutes until towering and deeply golden on top.
Brush with Honey Butter: Whisk melted butter and pure honey together. Immediately brush generously over hot biscuits as soon as they emerge from the oven. Sprinkle with flaky salt. Serve steaming warm!