Preheat an oven to 425 degrees F (220 degrees C). Lightly grease a baking sheet. Set aside.
To make the shortcakes, in a bowl, stir together the flour, sugar, baking powder, baking soda and salt. Using 2 knives or a pastry blender, cut in the butter until the mixture resembles coarse meal. Stir in the sour cream and egg until moistened. Turn the dough out onto a lightly floured work surface and pat into a rough circle (the dough will be sticky). Working with about one-sixth of the dough at a time, shape into rough balls and place about 1 inch (2.5 centimeters) apart on the prepared baking sheet. Bake until golden brown, about 18 minutes.
Meanwhile, prepare the berries: if using strawberries, slice them. In a bowl, combine the fruit with sugar to taste. Stir, then let stand until ready to use.
Remove the shortcakes from the oven and let cool on the baking sheet on a rack. In a bowl, whip the cream with the vanilla until it holds soft peaks. To serve, split each pancake in half horizontally with your fingers and place a bottom half on each of 6 individual plates. Top generously with the sugared berries and whipped cream. Replace the top half and serve.
Recipe courtesy of Tori Ritchie, Cabin Cooking, Time-Life Books, 1998