Start the recipe by preparing the fruit, then set the fruit aside while prepring the biscuits to allow the juices to become syrupy. Pasteurized cream has a better flavor than ultrapasteurized. Many organic brands are pasteurized.
FOR THE FRUIT:.
Place 3 cups of hulled berries in a large bowl, and crush with potato masher. Slice remaining 5 cups berries and stir into crushed berries along with sugar. Set fruit aside to macerate for at least 30 minutes and up to 2 hours.
FOR THE SHORTCAKE:.
Adjust oven rack to lower-middle position and heat oven to 425F in workbowl of food processor fitted with metal blade, pulse flour, 3 tablespoons sugar, baking powder, and salt to combine. Scatter butter pieces over and process until mixture resembles coarse meal, about fifteen 1-second pulses. Transfer to medium bowl.
Mix beaten egg with half-and-half in measuring cup. Pour egg mixture into bowl with flour mixture. Combine with rubber spatula until large clumps form. Turn mixture onto work surface and lightly knead until it comes together.
Use your fingertips to pat dough into 9x6 inch rectangles about3/4 inch thick, being careful not to overwork dough. Flour 2 3/4 inch biscuit cutter and cut out 6 dough rounds. Place rounds 1-inch apart on small baking sheet, brushing tops with egg whites and sprinkle remaining 2 tablespoons sugar. (Biscuits can be covered and refrigerated for up to 2 hours before baking).
Bake until shortcakes are golden brown, 12-14 minutes. Place baking sheet on wire rack and cool cakes until warm, about 10 minutes.
FOR THE WHIPPED CREAM:.
As soon as shortcakes go into the oven, place nonreactive, deep bowl and beaters of electric mixer in freezer for 20 minutes. (If freezer is too crowded to accommidate bowl., place beater in bowl, fill with ice water, and chill on counter, When bowl and beaters are well chilled, dump out ice water and dry thoroughly).
While biscuits are cooling, remove bowl from freezer and add cream, sugar and vanilla. Beat on low speed until small bubbles form, about 30 seconds. Increase speed to medium and continue beating until beaters leave a trail, about 30 seconds. Increase speed to high and continue beating until cream is smooth, thick, and nearly doubled in volume, about 20 seconds for soft peaks.
When shortcakes have cooled slightly, look for natural crack around circumference. Gently insert your finger into the crack and split the shortcake in half.
Place each cake bottom on individual serving plate. Spoon portion of fruit, and then dollop of whipped cream over each cake bottom. Cap with top and serve immediately.