Preheat oven at 160C.
Put all the egg yolk mixture except the flours into a blender and blend until the dates are broken and hardly visible.
Fold in the flours and set aside.
Beat the egg whites until foamy then add the cream of tartar.
Beat until soft peaks are formed then rain in the sugar.
Fold the meringue into the egg yolk mixture, one third at a time.
Bake for 60 minutes.
I baked mine in a 26 cm tube pan, but I think a 23 cm one could yield a taller cake. Note that in a smaller pan, the cake has a higher chance of cracking.