Prehat oven to 190°C. Grease and sprinkle with sugar (Demerara preferable) an 8-inch square or round pan.
Sift together flour, sugar, baking powder, salt and spices (stir in aniseed). In a separate bowl, whisk eggs, honey, water and 2 tbsp rum. Add to dry mixture and stir to blend. Scrape better into prepared pan and spread to level.
Bake for 20 minutes, then reduce oven temperature to 160°C. Bake for about 30 more minutes, until a tester inserted in the center of the cake comes out clean. While still warm, brush top of pain d’epices with remaining 2 tbsp rum.