01 - Combine sliced strawberries and granulated sugar in a mixing bowl. Stir thoroughly and let rest for at least 20 minutes until juices release and berries soften.
02 - Preheat oven to 425°F. Line a baking sheet with parchment paper and set aside.
03 - In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt until evenly distributed.
04 - Add cold cubed butter to the flour mixture. Using a pastry cutter or your fingertips, work the butter in until the mixture resembles coarse crumbs with some pea-sized pieces remaining.
05 - Pour in cold buttermilk and vanilla extract. Stir gently just until the dough comes together; avoid overmixing to keep shortcakes tender.
06 - Turn dough onto a lightly floured surface and pat into a 1-inch thick round. Cut out 6 rounds using a biscuit cutter, pressing straight down without twisting.
07 - Place rounds on the prepared baking sheet. Bake for 12 to 15 minutes until tops are golden brown. Transfer to a wire rack to cool completely.
08 - Beat heavy whipping cream, powdered sugar, and vanilla extract with an electric mixer or whisk until soft peaks form. Do not overwhip.
09 - Split each cooled shortcake in half horizontally. Spoon macerated strawberries and their juices generously over the bottom half. Add a dollop of whipped cream, then place the top half. Finish with additional berries and cream as desired. Serve immediately.