In a medium bowl, combine the sliced strawberries and granulated sugar. Toss gently to coat the strawberries in sugar. Cover and let sit for at least 15 minutes to allow the strawberries to release their juices, creating a syrup.

Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper.

In a large mixing bowl, whisk together the flour, baking powder, baking soda, salt, and granulated sugar until well combined.

Add the cold butter cubes to the flour mixture. Using a pastry cutter or your fingers, work the butter into the flour until the mixture resembles coarse crumbs.

Make a well in the center of the mixture and add the buttermilk and vanilla extract. Stir gently with a spatula until just combined. Do not overmix; the dough should be slightly sticky.

Turn the dough out onto a floured surface and gently pat it into a rectangle about 1-inch thick. Cut out shortcakes using a round cutter or a glass.

Place the shortcakes on the prepared baking sheet, spacing them about 2 inches apart. Bake in the preheated oven for 12-15 minutes or until golden brown.

Remove from the oven and allow to cool slightly on a wire rack.

In a large mixing bowl, combine the cold heavy cream, powdered sugar, and vanilla extract. Using an electric mixer, beat on medium-high speed until soft peaks form. Be careful not to overwhip, as this can turn the cream into butter.

Slice the cooled shortcakes in half horizontally. Spoon a generous amount of the macerated strawberries (with their juices) onto the bottom half of each shortcake.

Top the strawberries with a dollop of whipped cream, then place the top half of the shortcake over the cream.

Serve immediately, garnished with additional strawberries and whipped cream if desired.