Boil sugar and water until 250 degrees or when it forms a hard ball when you drop a few drops in a cup cold water. (It helps to have a candy themometer).
Place marshmallow cream in large mixing bowl. When the sugar water is ready, pour in a slow, thin stream the hot syrup while the mixer is on slow speed. After all syrup is in the cream, add vanilla and if desired, nuts, and put mixer on medium and beat until the cream forms a stiff peak.
Drop by spoonful on waxed or parchment paper. When cool, place in tight container and enjoy!
P.S. It will make better on a low humidity day.