For the Vanilla Cake: Whisk together 2 cups plain flour, 2 ½ tsp baking powder, and ¼ tsp salt.
Beat 4 large eggs on speed 6 for 30 seconds. Pour in 1 ½ cups caster sugar over 45 seconds with the mixer still on. Beat on speed 8 for 7 minutes until tripled in volume.
Add the dry ingredients in 3 batches, beating for 5 seconds in between. Stop beating as soon as you can no longer see flour.
Heat 1 cup milk and 115g unsalted butter until butter is melted. Pour this hot mixture into the bowl with the batter. Add 3 tsp vanilla extract and 3 tsp plain oil. Whisk until smooth.
Pour the tempered mixture into the cake batter slowly while beating on Speed 1. Scrape down the sides and give a final 5-second beat until smooth.
Bake in 3 x 20cm/8” lined cake pans for 23 minutes.
Cool in the pans for 10 minutes, then turn out upside down on a rack to cool completely.
For the Chocolate Frosting - Chocolate Base: Melt 200g dark chocolate chips with ¾ cup thickened cream.
Add ¼ cup dutch cocoa powder and mix until smooth.
For the Frosting: Beat 100g softened unsalted butter until creamy.
Gradually add 2 cups sifted icing sugar, beating until combined.
Add 250g cream cheese and beat until smooth.
Add ½ cup cold thickened cream and ¼ tsp salt. Beat until light and fluffy.
