Mix together flour, sugar, salt, baking powder, and baking soda in a medium bowl.

Slice cold butter into cubes and use a pastry knife or potato masher to cut butter into dry mixture until no large chunks of butter remain.

Add buttermilk and milk and stir with a spoon until dough forms.

Roll out to 1/2-inch thick on a floured surface.

Cut biscuits with a 3-inch biscuit cutter and arrange on a lightly greased or parchment paper lined baking sheet.

Bake for 22 to 24 minutes or until tops begin to turn light brown.

Remove biscuits from the oven and cool for a couple of minutes, then brush each biscuit top with melted butter.