Super Creamy Cake with a Unique Chocolate Filling

Instructions

For the Chocolate Filling:

1. Place 5 large eggs in a bowl. Add the sugar and cocoa powder. Mix everything with a whisk for 2-3 minutes until well combined and smooth. If preferred, use an electric mixer to ease the process.
2. Sift the flour over the mixture, then whisk until well incorporated.
3. Gradually add the milk: start with half a cup, mix well, then add another cup, mix, and finally add the remaining milk, ensuring each addition is well incorporated.
4. Strain this mixture into a large saucepan. *Note: It's important to use a large saucepan because you will need to stir vigorously later on, and a larger saucepan prevents spills and splashes.*
5. Turn the heat to medium-low. Avoid high heat to prevent burning. Stir continuously with a silicone spatula, scraping the bottom and sides to prevent the mixture from sticking.
6. Continue stirring until the mixture starts to thicken. It will thicken in lumps, which is normal. When it begins to form lumps, stir vigorously to break up any flour pockets and ensure a smooth consistency.
7. The mixture should become quite thick, similar to a thick brownie batter. Once it reaches this consistency, stir for another 2-3 minutes on low heat to cook the flour, eliminating any raw taste.
8. Turn off the heat, add vanilla extract, and mix to incorporate.
9. *Note: If the mixture has lumps, pass it through a sieve, pressing with a spatula, to ensure a smoother texture.*
10. Spread the mixture onto a large baking sheet to allow it to cool faster, and cover it with plastic wrap in direct contact with the surface. Let it cool completely at room temperature.
11. Once the mixture has cooled to room temperature, transfer it to the bowl of an electric mixer. Beat on medium speed for about one minute until creamy.
12. Add room-temperature butter and continue to beat until the mixture is smooth, creamy, and thick, with a texture slightly softer than buttercream. Scrape the bottom and sides of the bowl regularly with a spatula to ensure even mixing.
13. *Note: Ensure the chocolate cream and butter are at room temperature for easier incorporation. 

Assembling the Cake:

1. After the cream is ready, reserve about one and a half cups of the chocolate cream for decoration.
2. Soak ladyfingers cookies in milk, one at a time. Dip the cookies quickly to prevent them from becoming soggy.
3. On a serving plate, arrange the ladyfingers to form a layer that measures about 6x9 inches (15x23cm).
4. Place an adjustable rectangular cake ring around the layer of ladyfingers to hold the shape of the cake. If you don't have a cake ring, use a strip of acetate or parchment paper to contain the layers.
5. Spread half of the remaining chocolate cream over the ladyfinger layer. I like to use a piping bag fitted with a round tip to ensure an even layer, especially on the sides of the cake. 
6. Add another layer of soaked ladyfingers on top of the cream.
7. Spread the other half of the chocolate cream over this second layer of ladyfingers.
8. Add a final layer of soaked ladyfingers on top.
9. For decoration, use the reserved chocolate cream in a piping bag fitted with a 1M tip to create rosettes or other designs on the cake. Garnish with chocolate bonbons and chocolate wafer sticks.
10. Refrigerate for at least 4 hours or until serving time. 
11. After chilling, remove the cake ring and serve.