Refrigerate a bowl for 5 minutes to get it cold. Preheat the oven to 425ºF.

In the refrigerated bowl, add the flour, baking soda, cream of tartar, sugar and salt.

Cut the cold butter into small cubes (or use a cheese grater and grate the cold butter) and add to the flour mixture.

Using a pastry cutter, cut the butter in with the flour mixture until the butter is mostly mixed in. It is okay if there are small pieces of butter. Feel the flour mixture with your fingers and "snap" any large chunks of butter between your fingers to make them smaller. Set aside.

In a small bowl, whisk together the egg, buttermilk, zest and vanilla. Set aside.

Make a well in the flour in the center of the flour. Pour in the milk mixture.

Use a rubber spatula to mix the batter, just until barely combined.

Then fold in the fruit. Be careful not to overmix.

Sprinkle a couple tablespoons of flour onto a pastry mat.

Turn the dough out onto the pastry mat. Turn it over so the floured side is up. Make a disk that is about 1¼ inches thick and about 8” in diameter..

Use a knife to cut the disk into 8 triangles (or 6 for large scones), as if you were cutting a pie.

Place the scones on a baking sheet lined with parchment paper.

Sprinkle the tops of the scones with raw sugar.

Bake immediately for 12 minutes (or up to 14 minutes for large size scones).

While the scones are baking, whisk together the powdered sugar, vanilla and heavy cream in a small bowl.

While the scones are still warm, spoon the glaze over the scones, spreading gently to cover the tops.

Allow the scones to cool for 3-5 minutes then remove them to a wire rack to cool completely.