Preheat oven to 350F degrees.
Sift together sugar, flour and set aside.
With an electric mixer and whisk attachment, meat together egg whites, cream and tartar, salt and vanilla until soft peaks begin to form.
Fold in the flour and sugar mixture gently, being careful not to deflate the egg whites.
Gently spoon the cake batter into an ungreased 10 inch tube pan. Bake for 35 to 40 minutes until golden brown on top.
Turn the pan upside down to allow to cool completely.
When ready to serve, run a knife around the edge of the pan to release the cake. Dust with powdered sugar and top with fresh berries.