Preheat oven to 450°F. Line a baking sheet with parchment paper. Set aside.

Whisk the flour, sugar, baking powder, and salt in a bowl. Add the butter and toss with flour. Cut in the butter using a pastry cutter, 2 knives, or your fingers until it resembles coarse crumbs.

Whisk together the egg, cream, and vanilla in a separate bowl. Make a well in the center of the flour and pour the egg mixture into the hole.

With a spatula, mix the ingredients just until moistened. You want the dough to come together when squeezed. Add more cream slowly, one tablespoon at a time. Keep adding until the dough reaches a soft consistency. It should be soft enough to easily drop from a spoon or scoop.

Using a large spoon or scoop, drop the shortcake dough onto the prepared baking sheet. A spoonful about 2-3 inches wide should yield about 8 - 10 shortcakes spaced 1 inch apart. Sprinkle with sparkling sugar, if desired.

Bake until the shortcakes are firm to the touch and golden brown, about 10 to 12 minutes.

While the biscuits are cooling on a rack, whip the cream. Combine the cream, sugar, and vanilla in a deep, large bowl using an electric mixer. Beat at medium to high speed until soft peaks form, for about 2 minutes.

Use a serrated knife to halve the warm shortcakes horizontally. Layer with a dollop of whipping cream topped with fresh strawberries. Cover with the top half of the biscuit, garnish with additional whipping cream, a spoon of strawberry sauce or strawberry jam, if desired, and a mint sprig.