Preheat oven to 160 °C (320°F) with the fan on and grease and/or line two 8 inch cake tins.

In a bowl, sift together flour, cornflour, baking powder, and salt; mix well and set aside.

Combine milk and vinegar in a small bowl; mix and set aside.

Separate the yolks and whites from the egg whites, ensuring you have 225g of egg whites for later use.

In another bowl, combine butter, vegetable oil, and sugar; cream together for 3 minutes until light and creamy using an electric mixer.

Gradually add egg whites in 3 batches on low-medium speed, mixing well in between each addition.

Mix in vanilla and almond flavouring along with half of the milk/vinegar mixture until well combined.

Add half of the dry ingredients to the wet mixture and gently fold in until just combined.

Fold in the remaining milk/vinegar mixture until just combined.

Add the remaining dry ingredients and gently fold until just combined; avoid overmixing.

Distribute the batter evenly into the prepared cake tins; bake for 30 minutes or until a toothpick comes out clean.

Allow cake layers to cool in the tins for about 15-20 minutes before turning them out onto a wire rack to cool completely.

For the buttercream, mix butter, icing sugar, vanilla, and cream in a stand mixer on low speed until combined, then mix on medium-high for 10 minutes.

Trim edges and level the tops of the cake layers if desired.

Place the first layer on a cake stand, spread frosting on top, add the second layer, and frost the top and sides of the cake as desired.