Add the flour, baking powder, and sugar to a bowl. Whisk together to incorporate air and mix evenly.

Add the egg and milk to the dry ingredients. Add the milk a little at a time while mixing to prevent lumps (be careful not to overmix).

Add the soy sauce and mirin to the batter.

Shape the sweet red bean paste into stick shapes about the size of imitation crab sticks.

Set up the variety sandwich maker with the mini taiyaki (poisson) plate and turn it on. Once the preheat light turns green, use a heatproof brush to lightly coat the bottom plate with melted butter (not included in ingredient list).

Slowly and gently pour the batter onto the preheated plate.

First, fill the tail section of the mold with batter so it’s just below the rim (about 2mm). Make sure the batter doesn’t flow into the body section yet. Once the tail is filled, pour batter into the body section, using a little less so it doesn’t overflow.

Place the prepared red bean paste sticks in the center of the batter, then pour a little more batter over the top. If you’re working slowly, the batter should be rising nicely at this point. If the surface is still below the rim, add a bit more batter.

Close the lid and set the timer for 4–5 minutes. Do not open the lid for at least 4 minutes, or the taiyaki won’t bake properly.

Remove the taiyaki with chopsticks or a similar tool. Enjoy!