Mix together the flour, salt, and baking powder and sift.
Gently mix in the water.
Next, add all the remaining ingredients and mix them together thoroughly.
Heat the griddle (or frying pan) and lightly oil.
Spoon the okonomiyaki mixture on the griddle and spread it into a round shape about 1.2 to 1.5 cm thick.
When air bubbles start to rise in the middle of the okonomiyaki, turn it over with a spatula and fry while pressing down on it slightly until done.
Spread the sauce over the okonomiyaki, top with mayonnaise if you like.
Sprinkle on the aonori and dried bonito. The okonomiyaki is now ready to eat.