- In a mixing bowl, whisk together the flour, baking powder, and cornstarch. 
- In another bowl, whisk the egg and sugar until combined. Add milk and vanilla extract. 
- Gradually pour the wet mixture into the dry, whisking until smooth. 
- Heat your taiyaki pan over medium heat and lightly grease it with oil. 
- Pour batter into one side of the mold, filling about 60% of the fish shape. 
- Add a spoonful of red bean paste (or other filling) in the center. 
- Cover with a bit more batter to seal the filling. 
- Close the pan and cook each side for 2–3 minutes, flipping until golden brown. 
- Remove and let cool slightly before serving.