Adjust oven rack to upper-middle position and heat oven to 450 degrees F. Lightly spray a baking sheet with nonstick cooking spray.
In a medium bowl whisk together the flour, sugar, baking powder, and salt. Stir in the heavy cream until a dough forms, about 30 seconds.
Empty the dough onto a floured surface and knead into a smooth ball, this will take about 30 seconds. On a floured surface pat the dough into a 1-inch thick circle. Using a 2 3/4 inch (or 3 inch) biscuit cutter, cut biscuits and place on the prepared baking sheet. Pat out dough scraps into a 1-inch thick circle and cut again.
Bake 25 minutes, or until the biscuits are golden brown. Transfer biscuits to a wire rack to cool. Cut biscuits in half and serve with whipped cream and berries. Biscuits can be served warm or at room temperature.
Vanilla Custard Pastry Cream
Beat the heavy cream and powdered sugar together in a medium bowl until it begins to thicken. Add the vanilla pudding mix and continue to beat the mixture until it becomes very thick.
Blueberry Filling
In a heavy, medium saucepan, add the blueberries, sugar, lemon juice and half the water. Bring to a boil.
Add the cornstarch to the remaining water (cold water is best). Stir to remove any lumps then add to the blueberry mixture. Continue to boil until thickened; about 1 minute.
Whipped Cream
Add whipping cream, powdered sugar and vanilla extract to the chilled bowl of a standing mixer (or chilled mixing bowl). and beat for 60-90 seconds until stiff peaks form.