Preheat oven to 180°C (350°F), grease and line two 8-inch round cake pans.
Cream together softened butter, oil, and sugar until smooth.
Beat in eggs one at a time, then mix in vanilla extract.
In a separate bowl, mix flour, cornflour, baking powder, baking soda, and salt.
Gradually add dry ingredients to the wet mixture, alternating with milk, lemon juice, and zest.
Pour batter evenly into pans, bake for 32-35 minutes until done.
Let cakes cool in pans for 5 minutes, then transfer to wire racks to cool completely.
Whisk egg whites, sugar, and lemon juice over simmering water until thick and glossy.
Place one cake layer on a plate, pipe meringue around the edge, fill center with lemon curd, then top with second cake layer.
Spread remaining meringue frosting over cake, torch lightly for meringue look, then serve and enjoy!