Custard-filled Taiyaki is a classic variation of this popular Japanese dessert. The batter for this taiyaki is made with flour, sugar, baking powder, and water. The fish-shaped mold is filled with a smooth and creamy custard filling, made with eggs, milk, sugar, and vanilla extract. The taiyaki is then cooked until golden brown, resulting in a crispy exterior and a warm, velvety custard filling. The combination of the slightly sweet taiyaki batter with the rich and creamy custard creates a heavenly dessert that is sure to satisfy your sweet cravings. Serve it warm for a comforting treat that will leave you wanting more.