In a large bowl, whisk together the flour, baking powder, salt, and sugar.
Slice the cold butter into cubes. Add the butter to the flour mixture. Using your fingers, work the butter into the flour until you have small lumps of butter throughout.
Add 1 cup white chocolate chips and the orange zest. Stir to combine.
Whisk one egg into the heavy cream. Pour liquid into the flour and butter mixture. Mix with a spatula to combine.
Turn the dough out onto a clean work surface. Divide the dough in half. Shape each half into a circle, approximately 5 inches in diameter and ¾ inches tall.
Cut each circle into 8 wedges. Place the 16 wedges on a baking sheet. Freeze for 30 minutes (this will ensure that the scones rise nicely).
Meanwhile, preheat the oven to 400°F.
Beat the other egg in a small bowl. Brush the tops of the scones with the egg wash.
Press the remaining ¼ cup white chocolate chips into the tops of the scones.
Sprinkle each scone with a half teaspoon of granulated sugar.
Bake for 15–18 minutes, or until the tops of the scones are golden brown. Serve with coffee or tea.