Ingredients
2 cups all-purpose flour
2 teaspoons baking powder
1/8 teaspoon salt
1/4 cup sugar  
1/3 cup butter or margarine, cubed  
1/2 cup whipping cream
1 large egg
1 1/2 teaspoons vanilla extract
1 egg white
1 teaspoon water
Sugar  

Preparation

1. Combine first 4 ingredients. Cut in butter with a pastry blender until mixture is crumbly.
2. Whisk together cream, egg, and vanilla; add to flour mixture, stirring just until dry ingredients are moistened.
3. Turn dough out onto a lightly floured surface. Pat dough to 1/2-inch thickness; cut with a 2 1/2-inch round cutter, and place on baking sheets.
4. Whisk together egg white and 1 teaspoon water; brush mixture over tops of scones. Sprinkle scones with additional sugar.
5. Bake at 425° for 13 to 15 minutes or until lightly browned.