Lightly grease 4 cookie sheets. Sprinkle with anise seeds. Set aside until needed.
Mix the flour and baking powder together in a bowl until well blended. Place the eggs, sugar, and vanilla in a large bowl; beat until light and frothy, 5 to 8 minutes. Slowly stir in the flour mixture until a thick dough forms.
Working with handfuls of dough, roll out the dough onto a lightly floured surface until 1/4 inch thick. Lightly sift confectioners’ sugar over the dough. Place springerle molds onto the dough; press down hard and evenly until the mold’s design registers in the dough. Remove the mold. Use a small knife to cut around each cookie, and place on prepared cookie sheets. Repeat, until all dough has been used. Cover the cookies with a lightweight cotton cloth, and allow to dry 8 hours, or overnight.
Preheat oven to 250 degrees F (120 degrees C).
Bake cookies in preheated oven until tops are pale brown and set, 25 to 30 minutes. Cool on a rack. Store in an airtight container.