Preheat oven to 180°C bake. Grease 2x 9 inch cake tins with butter and line with baking paper
Sift flour, sugar, baking powder, baking soda, and salt into a large bowl and whisk to combine
In a medium bowl, add the milk, eggs, oil, and vanilla. Whisk to combine
Add to dry ingredients, whisk together until well combined
Pour in boiling water and whisk well - the batter will be runny
Divide the batter into two tins
Bake at 180°C for 35 minutes or until skewer comes out clean
Let cool for 15 minutes in tins before removing to rack