In a large bowl, whisk together flour, baking powder, salt, and sugar.
Cut in the grated butter until the mixture resembles coarse meal.
Make a "well" in the center. Add milk and buttermilk. Stir gently until dough pulls away from the side of the bowl. Do NOT over mix.
Turn out onto floured surface, and gently knead 8-10 times. Pat dough out to 1 inch thick. Cut biscuits with a large cutter or juice glass dipped in flour. Repeat until all the dough is used. Brush off the excess flour. Place biscuits on lined baking sheet.
Brush with melted butter.
Bake for 15-18 minutes in the preheated oven, or until edges begin to brown.
Notes
Recipe can be cut in half and it can be made ahead of time wrapped tightly in sprayed plastic wrap, in the refrigerator up to 24 hour.Also note you can use 1/3 cup butter and 1/3 cup shortening in place of all butter.