|½ teaspoon||Baking Powder|
Sift flour, cocoa, baking powder and salt three times onto a sheet of waxed paper. Beat egg whites til thick and fluffy. Add sugar gradually while beating, then add egg yolks and vanilla. Mixture should be thick and lemony. Sift dry ingredients over egg mix and fold in gently. Prepare an edged cookie sheet by greasing and lining with waxed paper. Pour batter onto pan and spread evenly. Bake at 400øF about 12-15 minutes. When baked, remove from pan and roll in a damp tea towel, sprinkled with icing sugar.
When cool, unroll, trim any crusty edges and spread with whipped cream.
Roll up, wrap in towel and chill. Serve slices topped with whipped cream.