Make the batter by whisking the flour, cake flour, dashi, and soy sauce.
Brush the takoyaki maker with a generous amount of sesame oil. Make sure each mold and the outside as well since the batter will spill over.
Turn on the takoyaki maker and when it’s hot, pour the batter into each mold until it’s about 3/4 full.
Add 2-3 pieces of octopus to each mold and a few chopped scallions. Finish filling the mold with a little more batter (don’t worry if it overspills as the batter will continue cooking and the balls don’t need to perfect).
Let the batter cook for about 3 minutes, until the underside is golden brown and the batter almost fully cooked.
Carefully flip each takoyaki ball using a skewer and cook for an additional 1-2 minutes, until the bottom is golden brown. The takoyaki balls are ready when they are golden brown all around and the inside is pillowy.
Gently transfer them to a plate using a skewer or chopsticks.
Top with a good squirt of okonomiyaki sauce and mayonnaise, and sprinkle aonori and bonito flakes on top. Serve immediately.
Leftovers: It’s best to eat takoyaki fresh because the sauce eventually makes the dough soggy. If you happen to have leftover naked/unsauced octopus balls, keep them refrigerated in an airtight container. They will keep for about 2 days. Microwave for 20-30 seconds before eating.