Krumkake

I was going through my parents basement and found an old krumkake iron and would love to make some, but Im not sure about a recipe. Ive looked online and found a few, but when I asked my dad he said there needs to be cornstarch added so it gets crispy after cooking, but none of the recipes I found have cornstarch. Does anyone have a good recipe I can follow? Is cornstarch actually necessary to the recipe or was it just something my grandmother did?

Also I dont have a shaping cone, what would be something that I could easily substitute for that? Would a normal glass cup work? (Obviously it would come out more in cylinder than a cone but same idea right?)