Preheat oven to 400 degrees and set a rack in the middle level. For a large shortcake, butter an 8-inch round pan and line the bottom with a disk of parchment or wax paper, cut to fit. For individual shortcakes, line a cookie sheet with parchment or foil. For the dough, combine dry ingredients in a mixing bowl and stir well to mix. Add butter and rub in finely with fingertips, until mixture resembles coarse meal. Beat together egg and cream and stir into flour and butter mixture to make a soft dough. For large shortcake, spread the dough evenly in the prepared pan. For individual shortcakes, place dough on a floured surface and fold over on itself 3 or 4 times. Pat out dough about 1/2-inch thick. Cut out individual biscuits with a 2 2/3-inch cutter. Sprinkle top(s) of shortcake(s) with sugar. Bake about 25 minutes for large one, or until a knife or skewer inserted in center emerges clean. Bake individuals about 15 minutes. Cool the biscuit(s) on a rack. For the whipped cream, combine all ingredients and whip by hand or by machine until cream holds soft peaks. Set aside refrigerated until needed. To assemble shortcake(s) split biscuit(s) horizontally and place large one on a platter and individual ones on dessert plates. Spoon filling on bottom of large shortcake or divide among bottoms on individual ones. Top with whipped cream and biscuit top(s).