Mix dry ingredients together. Use a big mixing bowl because you want lots of room for the mixing process. Cut in the grated frozen butter using 2 forks - care not to overwork dough.
Whisk the wet ingredients together, then combine with dry ingredients. Turn out the dough onto counter and cut into wedges.
Brush with heavy cream or buttermilk. For a golden brown, extra crisp and crumbly exterior, brush with liquid before baking.
Refrigerate 15+ minutes. Bake until golden brown. Bake at 400F for 20-25 minutes.