In a large bowl, whisk together eggs, sugar, vegetable oil, aniseed oil and whisky until well blended. Gradually stir in flour until fully incorporated. Cover, and refrigerate overnight.
Preheat a pizzelle iron, and coat lightly with oil. Drop tablespoons of batter onto the centre of the patterns. Close the lid, and cook until steam no longer comes out, about 1 1/2 minutes. Check, and adjust cooking time if necessary. Carefully remove biscuits, cool and store in an airtight tin at room temperature.
Use crushed aniseeds if you can't find aniseed oil.