01 - Preheat oven to 425°F. Line a baking sheet with parchment paper.
02 - Whisk flour, sugar, baking powder, and salt in a large bowl. Cut in cold butter with a pastry cutter or fingers until mixture resembles coarse crumbs.
03 - Whisk milk, egg, and vanilla in a separate bowl. Pour into dry ingredients and stir until just combined.
04 - Drop dough by large spoonfuls onto the prepared baking sheet to make 6 mounds.
05 - Bake for 15–18 minutes until golden brown. Cool completely.
06 - Combine strawberries, sugar, and lemon juice in a bowl. Let sit for at least 15 minutes to macerate.
07 - Whip heavy cream, powdered sugar, and vanilla in a cold mixing bowl with an electric mixer until soft peaks form.
08 - Crumble or split shortcakes. Layer pieces in the bottom of 6 clear cups. Add strawberries with juice, then whipped cream. Repeat layers, finishing with whipped cream and a strawberry slice on top. Serve immediately.