Beat egg yolks well, add sugar, salt, water, flour and baking powder, mixing well.
Stir in nuts, dates and vanilla.
Beat egg whites till stiff and gently fold into batter.
Pour into a greased 8x8-inch pan and bake at 325 degrees for about 40 minutes, or till set when you jiggle the pan.
Cool, cut into squares and serve with whipped cream.