Preheat the oven to 180C (350F). Mist three 20cm (8 inch) cake pans with cake release and line with baking paper.
Put the flour, sugar, baking powder and bicarbonate of soda in a large mixing bowl and mix together to combine.
Add the softened butter, eggs, milk, vanilla and lemon zest. Start beating at lowest speed setting until ingredients come together. Increase the speed to maximum and beat until the batter is completely smooth – about 30 seconds to one minute.
Transfer batter to the prepared cake tins and level using a spatula. Bake for 25-30 minutes or until the cake is golden and feels springy to the touch.
Transfer cakes to a wire rack and cool completely before frosting.
Scoop the pulp out of the passion fruit and strain the juice into a bowl. Discard the seeds.
Beat all remaining ingredients together, on medium-low speed, until you have soft peaks. Add the passion fruit juice, a little at a time.
Brush the cake layers with vodka and passionfruit liqueur. Pipe a generous layer of frosting to sandwich the cake layers together.
Cover the cake with frosting, smoothing over top and sides. Chill and do a second layer of frosting for a smooth finish or leave the cake layers showing through for a semi naked effect.
Top cake with any remaining frosting or decorate with meringue kisses and the passionfruit pulp. Slice and enjoy!
