01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - In a mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt. Add the cubed cold butter and cut it in using your fingers or a pastry blender until the mixture resembles coarse crumbs.
03 - In a small bowl, whisk together the heavy cream and egg. Pour the wet mixture into the dry ingredients and stir gently just until the dough comes together.
04 - Turn the dough out onto a lightly floured surface and pat it into a ¾-inch thick round. Cut into small squares or rounds, about 1 inch in size, suitable for layering in individual trifles.
05 - Arrange the shortcake pieces on the prepared baking sheet. Bake for 12 to 15 minutes until golden brown on top. Transfer to a wire rack and let cool completely.
06 - Place the sliced strawberries in a bowl and toss with the granulated sugar and lemon juice. Let stand for 15 minutes until the berries release their natural juices.
07 - Using an electric mixer or whisk, beat the chilled heavy cream, powdered sugar, and vanilla extract on high speed until stiff peaks form.
08 - In individual serving glasses, layer shortcake pieces, macerated strawberries with their juice, and whipped cream. Repeat the layers once more, finishing with a dollop of whipped cream and a few fresh strawberry slices on top.
09 - Serve immediately, or cover and refrigerate for up to 2 hours before serving.