Macerated Strawberries: Remove the tops of the strawberries and slice them in thirds, longways. Combine them with the white sugar and stir until well combined. Set aside.
Shortcake Biscuits: Preheat oven to 220 °C (425°F) and line a sheet tray with parchment paper. In a large bowl combine flour, cornstarch, baking powder, baking soda, salt, and sugar. Mix until well combined. Add in the cold, cubed butter, and press into the dry ingredients until it resembles coarse crumbs. Add in the buttermilk and fluff together until you have a shaggy dough. Turn the dough out onto a floured surface and form a rectangle that is ¾ of an inch high. Cut out the biscuits and place them on the prepared tray. Sprinkle with sugar and bake for 15 minutes or until golden brown. Allow to cool for 20 minutes.
Whipped Cream: In a bowl combine heavy cream, sugar, and vanilla. Whip until medium-stiff peaks form.
Assembly: Cut a biscuit in half, cover the bottom with strawberries and juice, add whipped cream, and place the top half on. Add more whipped cream and strawberries on top. Serve immediately.