For the angel food cake, whip the egg whites with salt until quite stiff and slowly add the sugar, continuing to beat until the sugar is dissolved. Mix the flour, baking powder and almonds, add the orange zest and pour in the oil. Add the stiff beaten egg whites on top and fold in, do not stir!
Pour this mixture into a well-greased springform pan sprinkled with almonds and smooth it out. Place in the oven preheated to 180 degrees.
Mix vanilla sugar with cinnamon, briefly open the oven after about 10 minutes of baking (when a “skin” has already formed on the cake) and sprinkle the vanilla sugar/cinnamon mixture on the cake, bake for another 30 minutes, then do the first stick test.
When the angel food cake is done, remove and let cool.