what size pan(s) - it is not specified in the recipe or directions!

Baking recipes should always have the size and type of pan used and for sure the type and brand of flour used, and the dry ingredients should be given by weight and not volume, or both just to cover all potential bakers' preferences.

I trained in pastry at Le Cordon Bleu Paris in the early 1980s and I couldn't tell you exactly what size, shape, and type of pan you should use. It depends on what the batter ended up looking like and what the desired outcome of the texture and crumb is. It would take a couple of tries to perfect it, as well. It would definitely be nice to know what the recipe writer used, if for nothing more than a point of reference for one's own efforts.

Abridged version: recipe is garbage, find another one, there are plenty out there.