In a large mixing bowl, stir together the flour, granulated sugar, baking powder and salt. Cut in the butter with a pastry blender till mixture resembles coarse crumbs.
In another bowl, beat milk, 1/2 cup whipping cream and the egg yolk together till combined. Add to dry mixture and stir till just moistened.
Turn the dough onto a lightly floured surface; knead it 5 to 6 times or till nearly smooth. Pat or lightly roll dough till its 1/2 to 3/4-inch thick. Cut with a 2-1/2-to 3-inch biscuit cutter dipped in flour. Place scones 1 inch apart on a greased or parchment-lined baking sheet.
Bake in a 400 degree F oven for about 12 minutes or till scones just begin to brown on the edges. Remove scones from the baking sheet and cool in a wire rack for 5 minutes. Serve warm.
In a medium chilled mixing bowl, with chilled beaters, beat 1 cup whipping cream till cream begins to hold its shape. Add the sifted powdered sugar and vanilla. Beat the mixture till soft peaks form (tips curl).
Serve the warm scones with the whipped cream and fresh berries. Garnish with mint sprigs, if you like. Makes 10 to 12 servings.