Sift the dry ingredients (25 g cornstarch, 125 g cake flour, ½ tsp baking soda and ½ tsp baking powder) into a bowl and mix.
In a separate bowl add 20 g light brown sugar and 1 medium egg(s). Whisk until combined, then add ½ tbsp honey, 1 pinch salt, 1 drop vanilla essence, 1 tsp cooking oil and mix well. Finally, pour in 150 ml whole milk while whisking until smooth.
Make a well in the dry ingredients and add the liquid ingredients one-third at a time, whisking gently each time until the ingredients are combined and smooth.
Cover the bowl and rest in the refrigerator for 30 minutes.
Divide 240 g red bean paste into equal pieces for each taiyaki, approx 40g (2.5oz) each. Roll into cylinders, cover and store in the refrigerator until it's time to cook.
After 30 minutes have passed, grease both sides of the taiyaki pan with a thin layer of cooking oil. Use kitchen paper to spread it evenly into the grooves of the mold. Place one side of the mold onto the stove and turn the heat on low/medium-low. Heat for a few minutes.
Once hot, add 1 tbsp of batter to each heated mold and spread it around using the back of a spoon. Make sure to go over edges of the taiyaki shape to stop it from falling when you flip the mold.
Once it's set (cooked enough that it doesn't run out), flip so that the empty one is on the stove and add 1 tbsp of batter to each mold. Spread evenly with the back of a spoon.
Place an anko cylinder into the centre of each taiyaki.
Drizzle another tbsp of the batter over the top of the anko filling to act as a glue.
Close the mold and heat for another 1 1/2 to 2 minutes on each side. (This varies from stove to stove so make sure not to leave it unattended, you can flip it when you can smell the sweet, baked smell of taiyaki.)
Remove the cooked taiyaki from the mold and repeat until you've used all of the batter and anko.
Optional: Use kitchen scissors to trim around the edges to neaten up the shape.
Enjoy!