Beat the whites until foamy then add the sugar and continue whipping until stiff and glossy, about 3 minutes. Add the powdered sugar and whip very briefly just to incorporate. Spoon the meringue into a piping bag fitted with a small (1/4-inch) plain tip and pipe onto a parchment paper lined sheet pan. Make a small round flat base 1/2-inch in diameter, then pipe a ring of meringue at the edge of the base and spiral up to make it two rows high. Continue making vacherins in rows on the sheet pan. Dry them out on the top of an oven that has been on, or preheat the oven to 300 degrees, then turn it off and place the vacherin meringues in it 5 minutes later. Leave them over night to dry out until crisp. Using a pastry bag, pipe whipped cream in the center and top each one with a raspberry.