Preheat oven to 425 F. Line a baking sheet with parchment or a baking mat.

In a medium bowl, whisk together the flour, baking powder, 1 tablespoon fine sugar and salt. In a large bowl, whip the heavy cream with the remaining 2 tablespoons fine sugar until softly whipped. Measure out 1 cup of the whipped cream and stir into the flour mixture with a fork (chill the remaining whipped cream for later.) On a well-floured board, knead the dough several times until it comes together (add another tablespoon of cream if it is too crumbly to come together.) Divide the dough into 4 pieces and pat out each to 1/2-inch thickness. Using a 3-inch crinkle cutter, cut a round from each one and transfer to the baking sheet (knead together the scraps, you might be able to cut out one more biscuit.) Brush the tops with cream and bake 15 minutes or until lightly browned. Let cool until still warm.

At the same time, toss the brown sugar and grapes together in a bowl and spread on a baking sheet. Roast 10 minutes and toss with the basil. Let cool.

To serve, split each shortcake with a fork and place on the bottom of 4 serving plates. Spoon whipped cream over the bottoms and top with the grapes and the tops of the shortcakes. Serve immediately.