To make takoyaki, you’ll need a special takoyaki pan. There are a variety to choose from online and the reviews can vary. I had success with a round cast-iron 15-hole models on a gas stove as well as a self-contained device that combines a 20-hole molded pan and the heat source in the form of a cassette burner. (The yield and cook times are based off the latter model and will vary depending on the pan you use.) Experienced takoyaki makers typically cover the entire pan with batter, then cut through and scrape the batter on the surface into the holes. I find it easier to only fill the holes but feel free to experiment.