Begin by melting the butter in a small saucepan or microwave-safe bowl. Allow the butter to cool to room temperature before incorporating it into the batter to prevent the eggs from cooking prematurely.
In a mixing bowl fitted with the paddle attachment, combine the eggs and sugar. Beat on medium-high speed for approximately 2–3 minutes, or until the mixture becomes pale yellow and slightly thickened.
Add the cooled melted butter, vanilla extract, anise extract, and anise seeds to the egg mixture. Continue mixing until the ingredients are fully incorporated and the batter appears smooth.
In a separate bowl, sift together the all-purpose flour, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients, folding gently until the batter is just combined. Avoid overmixing, as this may affect the delicate texture of the pizzelle cookies.