Combine flour, sugar, baking powder and salt. Cut in butter until mixture resembles coarse meal. Combine milk, 1 whole egg and 1 egg yolk: mix into dry ingredients until moist. Turn out onto lightly floured board, knead lightly several times. Bring dough together to form ball, divide in half. Pat each half into a circle 8 inches in diameter. Place one circle onto greased baking sheet: cover lightly with chocolate chips. Top with remaining circle, pressing edges lightly together. Beat remaining egg white and spread on top; sprinkle generously with additional sugar. With sharp knife, slice halfway through top layer to form 6 wedges. Bake at 425° for 18 to 20 minutes, until golden brown. Transfer to rack to cool slightly.
Whip Cream: Add 1 cup of the berries, sweeten to taste. Serve wedges of warm scone cake with remaining berries and strawberry whipped cream.