Step 1

In a medium bowl, beat the egg. Mix in the milk, vanilla extract, and butter.

Step 2

In another medium bowl, sift together the flour, sugar, baking powder, and salt. Use a wooden spoon or spatula to gently fold into the liquid ingredients until just incorporated. Cover and refrigerate the bowl for at least 1 hour.

Step 3

Place a taiyaki pan over medium low heat. Lightly grease with vegetable oil.

Step 4

Once heated, fill one side of the taiyaki pan cavities 1/3rd full with the batter. Add a heaping tablespoon of Nutella in the center of the fish and cover with batter to fill out the fish shape. Be careful not to overfill. Close the pan and flip.

Step 5

Cook for about 2 minutes until golden. Flip and cook the other side until golden, another 2 minutes, checking the color periodically once it has had a chance to set.

Step 6

Transfer the golden taiyaki to a wire rack and repeat with the remaining batter and Nutella.