Preheat oven to 350°.
Lightly spoon flour into dry measuring cups; level with a knife. Combine flour, aniseed, baking soda, and salt, stirring well with a whisk. Place sugar and butter in a large bowl; beat at medium speed with a mixer until blended (about 2 minutes). Add eggs, one at a time, beating well after each addition. Add flour mixture to sugar mixture, beating just until blended. Turn dough out onto a lightly floured surface, and knead lightly 7 times. Shape the dough into a 12-inch-long roll. Place roll on a baking sheet coated with cooking spray; pat to 1-inch thickness. Bake at 350° for 40 minutes. Remove roll from baking sheet; cool 10 minutes on a wire rack.
Reduce oven temperature to 300°.
Cut roll crosswise into 22 slices. Place, cut sides down, on baking sheet. Bake at 300° for 10 minutes. Turn cookies over; bake an additional 10 minutes (cookies will be slightly soft in center but will harden as they cool). Cool cookies completely on wire rack.
Heat chocolate in a small heavy saucepan over low heat for 5 minutes or until melted; stir. Dip cookies, top sides down, in chocolate; allow excess chocolate to drip back into pan. Place cookies, chocolate sides up, on a baking sheet. Let stand 1 hour or until set.