Sift flour, baking powder and salt together. Grease and flour two mini chiffon cake pans.
Whisk eggs, cream of tartar and sugar until fluffy and stiff. Add orange rind and red dates. Continue to whisk for a few seconds. Beat in orange juice and corn oil. Lightly fold in sifted dry ingredients.
Turn batter into prepared pans and steam over rapid high heat for 25-30 minutes. Leave cakes in the mould till completely cooled, then remove cakes.