For the shortcake: (can also use your favorite store-bought shortcakes)
2 cups Flour
2 1/2 teaspoons Baking Powder
1/4 teaspoon Baking Soda
1/2 teaspoon Kosher Salt
1/3 cup Sugar
4 ounces Butter, chilled, cut into pieces
1/4 cup Buttermilk
1/4 cup Cream
For the shortcake:
Preheat oven to 425 °F and line a baking sheet with parchment paper.
In a food processor, combine the flour, 1⁄3 cup sugar, baking powder, baking soda, and salt. Pulse in the chilled butter until the mixture resembles coarse meal. Remove to a mixing bowl.
In a small bowl combine the egg, buttermilk, and ¼ cup cream.
Stir into the dry ingredients to form a moist dough. Add additional cream if needed.
On a lightly floured surface gently knead several times. Roll the dough out approximately ¾-inch thick and cut into 8 to 10 rounds, each 2-½ inches in diameter. Place the shortcakes on the prepared baking sheet. Brush tops with cream and sprinkle with sugar. Bake until lightly golden brown, about 15 minutes.
For whipped cream, use store bought or in a chilled bowl, with a chilled whip, beat 1-½ cups cream until lightly thickened. Add 1-½ tablespoons sugar and beat to medium soft peaks. Chill until ready to use.
With a serrated knife, cut shortcakes in half and set the bottoms on individual serving plates.
Divide the Mixed Berries among the shortcake bottoms, allowing some to run off each shortcake onto the plate. Top with whipped cream and add the shortcake top.