Prep: Preheat oven to 350°F (180°C). Have an 8x8 inch (20x20cm) baking pan ready (do not grease).

Make Custard Base: In a medium bowl, whisk 1 egg with 50g sugar and vanilla sugar until pale. Whisk in cornstarch until smooth. Gradually whisk in 250ml milk until fully combined. Pour this thin mixture into the bottom of your baking pan.

Make Cake Batter: In a separate bowl, whisk 2 eggs with 100g sugar and salt. Whisk in 100ml milk and oil. Sift in flour and baking powder. Whisk until a smooth, thick batter forms.

Assemble Magic: Spoon dollops of the thick cake batter evenly over the entire surface of the custard liquid in the pan. Using a spatula, gently and carefully spread it into an even layer to seal the surface. Do not mix. Sprinkle chopped almonds evenly over the top.

Bake: Bake for 35-40 minutes, until the top is a deep golden brown, the almonds are toasted, and a toothpick inserted into the cake layer comes out clean.

Cool & Set: Let the cake cool completely in the pan on a wire rack. This is essential for the custard layer to set.

Serve: Once cool, slice, reveal the layers, and enjoy!