Preheat your oven to 400°F. Line your baking sheet with parchment paper. This high temperature is critical — it creates the steam that gives the scones their lift and helps the cream caramelize into that gorgeous golden crust.
In a large bowl, whisk together the 2 cups of flour, 2 teaspoons of baking powder, 1/2 teaspoon of salt, and 1/4 cup of sugar. Make sure there are no lumps, especially from the baking powder. Whisking also aerates the flour, which helps make the scones lighter.
Stir the 2 tablespoons of orange zest into the dry ingredients. This coats the zest in flour and prevents it from clumping together later. You'll smell the orange oils immediately — that's exactly what you want.
Make a well in the center of the dry ingredients. Pour in the 1/2 cup of cold orange juice, 1 cup of cold heavy cream, and 2 teaspoons of vanilla extract. Stir with a fork just until a shaggy, slightly sticky dough forms. Stop the moment the flour streaks disappear — over-mixing develops gluten and makes them tough. I count to twelve stirs and stop. The dough will look rough and lumpy — that's perfect.
Use two spoons or a large cookie scoop to drop 8 equal mounds of dough onto the prepared baking sheet. Space them about 2 inches apart. Don't flatten them — the craggier and taller they are going into the oven, the more texture and height they'll have coming out. Rough edges get extra crispy, which is the best part.
Bake for 14–16 minutes, or until the bottoms are deep golden brown and the tops are lightly browned. A toothpick inserted into the center of a scone should come out clean or with a few moist crumbs. If you want to be precise, an instant-read thermometer inserted into the center should read around 200°F. Your kitchen will smell like a citrus grove.
Transfer the scones to a cooling rack and let them cool completely, about 15 minutes. I know it's hard to wait, but glazing warm scones will result in a thin, runny mess that slides right off into a puddle on your plate.
While the scones cool, make the glaze. In a small bowl, whisk together the 1 cup of powdered sugar, 1 tablespoon of orange zest, 1/4 teaspoon of vanilla extract, 1 tablespoon of cream or milk, and 1 tablespoon of fresh orange juice. Whisk vigorously until smooth and completely lump-free. The glaze should be thick enough to coat the back of a spoon but still flow slowly. If it's too thick to drizzle, add more orange juice a teaspoon at a time. If it's too thin, add more powdered sugar.
Drizzle the glaze over the cooled scones using a spoon or a whisk, letting it drip naturally down the sides. Watch it pool in the craggy cracks. Let it set for about 5 minutes before serving. The glaze will harden slightly, creating a beautiful, crackly, white shell that shatters when you bite into it.