Lemon Vanilla Custard Cream:

1. Mix the eggs with sugar, corn starch, salt, lemon zest and lemon juice until smooth. Add ¼ of the cold milk.
2. Heat up the remaining ¾ of the milk over medium heat. When it begins to boil, turn down to low heat and add egg mixture. Bring to a boil and stir continuously for 3-4 minutes until the cream thickens up.
3. Remove from the heat, add butter and mix until incorporated. Pour custard cream into a glass container and cover entire surface with plastic wrap to prevent the skin to form on the surface. Cool down the custard to room temperature.

Cake batter:

1. Preheat the oven to 350 degrees Fahrenheit.
2. Meanwhile cut a round shape of parchment paper and add it to a round pie dish.
3. In a large bowl, beat eggs with sugar until creamy, then add salt, orange zest, vanilla extract, oil and mix well.
4. In another bowl, mix the flour and baking powder. Incorporate flour to egg mixture using a whisk. Do not overmix the cake batter to avoid developing the gluten. The result should be a thick batter.

Assemble and decor:

1. Pour batter into round pie dish and level the surface.
2. Add the custard into a piping bag.
3. Pipe the custard in a diamond shape on top of the cake batter.
4. Decorate with almond slivers on top of the batter.
5. Bake at 350 degrees for 35-45 minutes or until golden brown on top and the cake batter is baked. Insert a toothpick or a thin skewer into center of the cake. If the toothpick comes out clean, with no streaks of batter is the sign the cake is done.
6. Remove from the oven and let sit cooling rack. After 30 minutes carefully remove the cake from the pie dish and place it onto a plate.
7. Dust with powder sugar on top.
8. Enjoy!