Meanwhile, place the egg whites in the bowl of an electric mixer fitted with the whisk attachment. When the sugar is almost ready, whisk the egg whites on high speed for 1 minute, until the whites are frothy. With the mixer still on high, slowly add the hot sugar to the egg whites. (I use a large spoon to start and then pick up the paper and pour the sugar in slowly.) Add the vanilla and continue to whisk on high for 10 minutes, until the meringue is at room temperature. It will be very thick and glossy.