2 pints strawberries, hulled and halved (quartered if large)
2 to 3 tablespoons granulated sugar, depending on the ripeness of the strawberries
2 teaspoons fresh lemon juice
2 cups cake flour, plus extra for shaping
2 teaspoons baking powder
3 tablespoons confectioners' sugar, plus extra for serving
1¼ teaspoons kosher salt
1 tablespoon lemon zest
10 tablespoons cold unsalted butter, cut into ¼-inch cubes, plus 2 tablespoons melted butter
1 cup sour cream
Whipped cream, for serving
1. Macerate the strawberries: In a medium bowl, stir together the strawberries, sugar and lemon juice. Set aside to macerate while preparing and baking the shortcakes, stirring the strawberries every 15 minutes or so.
2. Make the shortcakes: Add 2 cups of the cake flour, the baking powder, 3 tablespoons of the confectioners' sugar, the salt and lemon zest to a food processor and pulse to combine. Add the cold cubes of butter and pulse until the flour-butter mixture resembles coarse meal, about 15 one-second pulses. Add the sour cream and pulse until a soft dough forms, another 10 to 15 one-second pulses (don't overmix the dough).
3. Transfer the dough to a lightly floured baking sheet. Dust your hands with some of the flour and lightly flatten the dough into a 1-inch-thick rectangle about 6 inches wide by 9 inches long. Cut the rectangle into 6 equal-size pieces. Chill in the refrigerator for 30 minutes. Meanwhile, preheat the oven to 425°.
4. Remove the chilled shortcakes from the refrigerator and brush the tops with the melted butter. Bake until the tops become pale golden-brown, 12 to 14 minutes. Transfer the shortcakes to a wire rack to cool completely.
5. Break a shortcake in half crosswise. Place one half on a plate and spoon some of the strawberries with their juices over the top. Place a dollop of whipped cream over the strawberries and lean the other half of the shortcake over the whipped cream. Repeat with the remaining shortcakes. Dust each serving with confectioners' sugar and serve.