Please read again the list of ingredients : you will find the answer (80 grams i.e. 2.5 oz) to your questions. I believe that in this recipe, "corn" is actually "wheat"

This cake sounds very yummy but cannot find the quantity for flour. Please let me know.

I have read the English translation of this recipe and I now understand your concern since there is a mistake in the translation : what is described as "corn flour" is actually corn starch and to the 50 grams of it used for the mixture, add also 50 grams of wheat flour (missing in the list of ingredients. Sorry for that.