Beat eggs in a large mixing bowl until thick and lemon colored; gradually add sugar and butter; continue beating 10 minutes. Stir in anise.
Combine flour and baking powder in a medium mixing bowl; stir well. Add to egg mixture, stirring well.
Roll dough to 1/8-inch thickness on a lightly floured surface. Use a floured cookie mold or springerle rolling pin to imprint dough. Separate cookie squares using a knife. Place 2 inches apart on well-greased cookie sheets. Let stand, uncovered, in a cool, dry place 12 hours or overnight to set design.
Bake at 300° for 12 to 15 minutes. Remove from cookie sheets, and cool on wire racks.
The recipe yield will depend on the size and the shape of the springerle mold that you use and how much you re-roll the dough. We used a rectangular wooden mold that was about 5 inches x 3 inches and we got a yield of 10 cookies. If you use the smaller square or round molds, you'll get closer to 4 1/2 dozen.