Preheat the oven to 400°F (200°C). Line a large baking sheet with parchment paper.
Sift the flour, granulated sugar, baking powder, and salt into a large mixing bowl. Place the bowl in the freezer for about 10 minutes to thoroughly chill the dry ingredients.
Add the cold cubed butter. Use a pastry cutter, fork, or your fingertips to quickly work the butter into the flour until the mixture resembles coarse crumbs with some small pieces of butter remaining.
Add the Greek yogurt, 5 tablespoons heavy cream, and vanilla extract. Stir gently with a fork until a shaggy dough begins to form. If it remains too dry to hold together, add the remaining cream a little at a time.
Gently fold in the raspberries and white chocolate chips. Avoid excessive mixing or crushing the berries.
Transfer the White Chocolate Raspberry Scones dough to a lightly floured work surface. Pat it gently into a circle approximately 9 inches across.
Cut the dough into 8 equal wedges with a sharp knife. Arrange the wedges approximately 2 inches apart on the prepared baking sheet.
Lightly brush the tops with heavy cream. Bake for 25–30 minutes, or until the edges are lightly golden and the centers are baked through.
Transfer the scones to a wire rack and allow them to cool.
For the glaze, whisk powdered sugar, 1 tablespoon milk, and vanilla until smooth. Add additional milk gradually if necessary to reach a drizzling consistency.
Drizzle the vanilla glaze over the cooled scones and allow it to set before serving.