In a medium bowl, whisk together 50ml of milk, corn flour, egg yolks, and 50g of sugar until smooth. Heat 450ml of milk with another 50g of sugar over medium heat, stirring until dissolved. Slowly add about a third of the egg mixture to temper it, then whisk back into the saucepan. Stir constantly on medium heat until thickened and bubbly, about 5-7 minutes. Remove from heat and cover with plastic wrap, pressing directly on the surface.

Preheat your oven to 180℃ (350℉) and grease two 22cm cake tins. In a large bowl, whisk together flour, baking powder, and salt. Beat the room temperature eggs with a mixer for about 7 minutes, gradually adding 375ml of caster sugar until the mixture triples in volume and becomes pale and fluffy.

Gently fold the flour mixture into the egg mixture in three additions. In a small saucepan, melt the 115g of softened butter with a splash of milk over medium heat. Add the melted butter mixture, a dash of vanilla, and 15ml of vegetable oil to the batter, mixing gently until smooth.

Divide the batter evenly between prepared tins and bake for about 30 minutes or until a toothpick comes out clean. Let the cakes cool in the tins for 15 minutes before transferring to wire racks to cool completely.

Once cooled, slice each cake into two equal discs to create four layers. Spread an even layer of cooled custard on the bottom layer and repeat with remaining layers. Finish the top layer with a thick layer of custard and sprinkle 125ml of toasted almond flakes on top.