Mix the eggs and sugar with an electric hand mixer until fluffy. Sieve in half of the flour and baking powder then mix at low speed. Mix in the orange juice and vegetable oil. Sieve in the rest of the flour. Add zest and aniseed and mix well.
Pour boiling water over the sultanas and pat completely dry with a kitchen towel. Mix the walnuts and saltanas in a bowl and mix in the remaining 1 tablespoon flour. Fold into the cake mixture.
Pour the batter into two greased loaf tins and flatten out. Bake for an hour in the preheated oven. The cakes are done when a skewer inserted into the centre comes out clean. If the cake still isn't cooked through but the top is getting too dark cover with aluminium foil and bake a further 10 minutes.
Allow to cool for 5 minutes and then remove it from the cake tin and allow to cool completely on a cake rack.