1. Heat a nonstick pizzelle iron. In a large bowl, sift together, flour, baking powder, and a pinch of salt; set aside.
2. In a large bowl, whisk the eggs. Slowly add the sugar, and continue mixing until well-blended. Whisk in the vanilla extract and the lemon extract. Slowly add the cooled butter in a steady stream, whisking continuously until the batter is smooth.
3. Slowly add the sifted flour mixture, and keep whisking until the flour is completely incorporated into the batter. Do not overbeat.
4. Fill a pastry bag fitted with a 1/4-inch or 3/8-inch plain tip with batter. Pipe 1 1/2 tablespoons of batter in a circle in the center of each pattern on the heated pizzelle iron. Close the iron and seal with the clasp. Cook for 50 to 60 seconds. Using a small spatula, remove pizzelles, and place on wire rack to cool.