Toss the sliced strawberries with granulated sugar and lemon juice. Let them rest for 30 minutes until juicy.Preheat the oven to 425°F (220°C) and line a baking sheet with parchment paper.In a large bowl, whisk together the flour, sugar, baking powder, and salt.Cut in the cold butter until the mixture resembles coarse crumbs.Stir together the heavy cream, egg, and vanilla, then gently mix into the dry ingredients until a soft dough forms.Pat the dough to about 1-inch thick and cut into 8 biscuits.Place the biscuits on the prepared baking sheet, sprinkle with coarse sugar if desired, and bake for 16–18 minutes until golden.Cool the biscuits on a wire rack.Beat the heavy cream, powdered sugar, and vanilla until soft peaks form.Slice each biscuit in half, layer with strawberries and whipped cream, then top with the remaining biscuit half. Add more strawberries and whipped cream before serving.
