In a large bowl, combine the sliced strawberries, sugar, lemon juice, and zest. Gently toss to coat evenly. Let this mixture sit at room temperature for at least 30 minutes to macerate.
Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper.
In a large bowl, whisk together the flour, 1/4 cup sugar, baking powder, and salt.
Using a pastry cutter or your fingertips, cut the cold butter into the dry ingredients until the mixture resembles coarse crumbs with some pea-sized pieces remaining.
In a separate small bowl, whisk together the heavy cream, egg, and vanilla extract until well combined.
Pour the wet ingredients over the flour-butter mixture and stir just until combined. Avoid overmixing.
Turn the dough onto a lightly floured surface and gently pat it to a 3/4-inch thickness. Using a 2 1/2-inch round biscuit cutter, cut out shortcakes. Re-roll scraps once to cut additional shortcakes.
Place the shortcakes on the prepared baking sheet, brush the tops with a little heavy cream, and sprinkle with the remaining 2 tablespoons of sugar and coarse sugar if using. Bake for 15-18 minutes, or until golden brown.
While the shortcakes are cooling, prepare the whipped cream. In a chilled bowl, combine the heavy cream, powdered sugar, vanilla extract, and pinch of salt. Beat until soft peaks form.
Once the shortcakes have cooled for about 10 minutes, split them horizontally. Place the bottom half on a serving plate, top with macerated strawberries (including juice), add a dollop of whipped cream, and crown with the shortcake top.