Line a large sheet pan with parchment paper and make room in the freezer for the pan. If you have smaller pans, you can use two instead. In a large spouted measuring cup, whisk together the sourdough discard, heavy cream, 1 large egg, vanilla extract, orange peel, and orange juice until the mixture is smooth. Set this wet mixture aside for later.

In a large mixing bowl, whisk together the all-purpose flour, corn starch, cane sugar, baking powder, and fine sea salt. Take the cold unsalted butter straight from the fridge and grate it into the flour mixture using the largest holes on a grater. Toss the grated butter with the flour until the butter pieces are coated, working quickly to keep it cold. Add the sweetened dried cranberries to the bowl and toss again to distribute them evenly. If you notice the butter getting soft, place the bowl in the freezer for 10 minutes before continuing. I find that chilling the butter here makes the scones even flakier.

Make a well in the center of the flour, butter, and cranberry mixture (from Step 2). Pour the wet ingredients (from Step 1) into the well. With a silicone spatula, gently stir just until the flour is moistened—it's ok if there are still some dry patches. Using your hand, scoop and fold the dough over itself 10-12 times, creating a shaggy, layered mixture. This folding helps build flakiness in the scones. Don't overwork the dough; it should remain cold and a bit scruffy.

Transfer the shaggy dough to a floured work surface. Gently knead or press the dough together to form a rough disk, working quickly to keep it cold. Roll the dough out to a disk about 3/4 to 1 inch thick and 7 1/2 to 8 inches in diameter. Cut the disk into eight equal wedges by pressing a knife down in one motion per cut. Avoid sawing to help keep the edges clean.

Arrange the scones evenly on the prepared parchment-lined baking sheet, leaving space between each. Place the pan in the freezer for 30 minutes to chill the dough. If you want to prepare them ahead of time, you can freeze the scones until solid and then transfer them to a freezer bag or airtight container for baking at a later date.

While the scones are freezing, preheat the oven to 425°F (218°C) with a rack in the center. In a small bowl, whisk together the remaining egg and the tablespoon of water to make an egg wash. Once the scones are chilled, brush the tops lightly with the egg wash using a pastry brush, then sprinkle generously with turbinado sugar. I like to be extra generous with the sugar for a crunchy top.

Bake the scones in the preheated oven for 5 minutes, then reduce the temperature to 375°F (190°C) and continue baking for 15-20 minutes more. The scones are done when their internal temperature reaches 200-205°F (93-96°C) and they are golden. Cool slightly before serving. For a drier scone, I like to turn off the oven after baking, leave the scones inside, and prop the door open for about 10 minutes. Enjoy your scones warm, simply as they are or with orange marmalade or clotted cream.