Using chilled bowl and beaters, whip cream until soft peaks form. Add sugar and vanilla and continue to beat until firm peaks form. To assemble shortcakes, split each one across the middle and place a dollop of whipped cream on bottom half. Top with a few strawberries, a little more whipped cream, then top with the second shortcake half. Add one more dollop of whipped cream and top with a single strawberry. Serve immediately.