Ingredients

For the Filling:

• 50 g cocoa powder (½ cup)
• 40 g cornstarch (⅓ cup)
• 800 ml milk (3 ⅓ cups)
• 100 g dark chocolate (3.5 oz)
• 8 g vanilla sugar (1 tbsp)
• 50 g sugar (¼ cup)
• 8 g agar-agar (1 tsp)
• 200 g milk chocolate (7 oz)
• 300 g cream (1 ¼ cups, 33% fat)
• 300 g chocolate biscuits (about 20-24 biscuits)
• 50 g walnuts (chopped, about ½ cup)

For the Chocolate Glaze:

• 100 g dark chocolate (3.5 oz)
• 50 g cream (¼ cup, 33% fat)

Step-by-Step Instructions

1. Prepare the Filling

1. Combine dry ingredients: In a medium saucepan, mix the 50 g cocoa powder, 40 g cornstarch, 50 g sugar, and 8 g vanilla sugar. Stir well to ensure the ingredients are evenly distributed.
2. Add the milk: Gradually pour in 800 ml of milk, whisking constantly to prevent lumps from forming.
3. Cook the mixture: Place the saucepan over medium heat and cook, stirring continuously, until the mixture thickens to a pudding-like consistency. This process should take about 8-10 minutes.
4. Add chocolates and agar-agar: Once the mixture has thickened, remove it from heat and immediately add 8 g of agar-agar, 100 g dark chocolate, and 200 g milk chocolate. Stir until the chocolate has melted completely and the mixture is smooth and glossy.
5. Cool slightly: Let the mixture cool for 10-15 minutes, allowing it to thicken a bit more.

2. Prepare the Cream

1. Whip the cream: In a separate bowl, whip 300 g of cream until soft peaks form. Be careful not to overwhip, as the cream should remain light and airy.
2. Fold the cream: Gently fold the whipped cream into the slightly cooled chocolate mixture. Be careful not to deflate the cream; use a spatula to fold the ingredients together until well combined.

3. Assemble the Layers

1. Layer the biscuits: In a serving dish (about 9×13 inches), arrange a single layer of chocolate biscuits at the bottom. Break them into smaller pieces if necessary to fit the dish.
2. Add the chocolate cream: Pour half of the chocolate cream mixture over the biscuit layer and spread it evenly using a spatula.
3. Repeat layers: Add another layer of chocolate biscuits on top of the cream, followed by the remaining chocolate cream.
4. Add walnuts: Sprinkle 50 g of chopped walnuts evenly over the top layer of chocolate cream.

4. Prepare the Chocolate Glaze

1. Heat the cream: In a small saucepan, gently warm 50 g of cream over low heat until it’s just about to simmer.
2. Melt the chocolate: Add 100 g of dark chocolate to the warm cream and stir continuously until the  chocolate is fully melted and the glaze is smooth and glossy.

5. Decorate

1. Drizzle the glaze: Using a spoon or piping bag, drizzle the chocolate glaze over the top of the dessert in a decorative pattern, such as a lattice, or simply cover the top for a smooth finish.

6. Chill and Serve

1. Refrigerate: Place the assembled dessert in the refrigerator and let it chill for at least 2 hours to allow the layers to set properly.
2. Serve: Once set, slice the dessert into squares and serve chilled. The layers of creamy chocolate and crunchy biscuits create a delightful contrast in texture, while the walnut topping adds a nutty crunch.