Stir the strawberries with ¼ cup of sugar in a bowl. Let them sit for at least 30 minutes, stirring once or twice, until juicy.
Heat the oven to 425°F. Line a sheet pan with parchment paper.
In a large bowl, whisk the flour, ¼ cup of sugar, baking powder and salt. Work in the cold butter with your fingers or a pastry cutter until the mixture looks like coarse crumbs with a few pea-size pieces.
Pour in ¾ cup of milk and stir just until a shaggy dough forms.
Turn the dough out onto a lightly floured surface and pat it into a rectangle about ¾ inch thick. Cut out biscuits with a 2½-inch cutter, pressing straight down. Gather the scraps, pat them out and cut again to make 8.
Place the biscuits on the pan. Brush the tops with milk and sprinkle with the remaining tablespoon of sugar. Bake for 13–15 minutes, until golden. Cool for 10 minutes.
Whip the cream with the powdered sugar and vanilla until soft peaks form.
Split the biscuits. Spoon strawberries and their juice over the bottoms, add whipped cream and set the tops on.