Preheat oven to 400 degrees F.
Whisk together flour, baking soda, baking powder, sugar, and salt.
Grate frozen butter using the large holes on a box grater. Add butter and zest of the orange and lemon to dry mixture. Rub the butter and zest into the flour mixture to lightly coat.
Make a well in the middle of the mixture. Add cranberries to well.
Whisk together discard and buttermilk, then pour over the cranberries. Mix dough together with spatula until it becomes thick, then gently with your hand to bring the dough together.
Tip dough out onto counter and gently knead for 15 seconds with floured hands - the dough will be shaggy and a little bit dry like biscuit dough. Mound into a ball, about 5-6 inches in diameter, dough will be shaggy. Do not flatten the top of dough.
Brush dough with a little more buttermilk and sprinkle with coarse sugar. Use a knife to make a 3/4 inch deep x in the middle of the dough.
Bake for 40-45 minutes, until golden brown and center is cooked through. Let cool for 10 minutes. Then eat with butter and honey.