Toss the sliced strawberries with 2 tablespoons sugar. Let stand while preparing biscuits, stirring once or twice.
Heat oven to 425°F (220°C) and line a baking sheet with parchment.
Whisk flour, baking powder, remaining sugar, and salt. Cut in cold butter until pea-size pieces form, then stir in buttermilk just until shaggy.
Pat dough 3/4 inch thick on a lightly floured surface and cut six biscuits. Place on the sheet, brush with buttermilk, and sprinkle coarse sugar.
Bake 13 to 15 minutes until risen and golden. Cool at least 10 minutes.
Whip cold cream and vanilla to soft peaks. Split biscuits and layer with strawberries, their juices, and whipped cream.