Step-by-Step Instructions
1. Prepare the Custard
In a medium saucepan, whisk together the sugar, cornstarch, and egg yolks with a splash of the milk to create a smooth paste. Gradually pour in the remaining milk while whisking constantly. Place over medium heat and stir until the mixture thickens into a heavy, pudding-like consistency. Remove from heat and stir in the butter and vanilla.
2. The First Layer
Line the bottom of a rectangular springform pan or a deep baking dish with a single, tight layer of biscuits. If necessary, break the biscuits to fit the corners perfectly.
3. Build the Architecture
Pour one-third of the hot custard over the first layer of biscuits, spreading it evenly to the edges. Place another layer of biscuits directly on top of the custard. Repeat this process until you have three layers of biscuits and three layers of custard, ending with a custard layer on top.
4. The Ganache Pour
Heat the heavy cream until it just begins to simmer, then pour it over the chopped chocolate. Let it sit for one minute before stirring into a glossy, dark liquid. Pour this ganache over the top of the cake, tilting the pan to ensure it covers the entire surface.
5. The Final Flourish and Set
Top the wet ganache with a generous layer of chocolate shavings. Place the cake in the refrigerator for at least 6 hours, though overnight is best. This allows the biscuits to soften and the custard to set firmly enough to produce the sharp layers seen in the image.
Why This Recipe Works
| Feature | No-Bake Custard Slice | Traditional Baked Cake |
| Effort | Low (No oven required) | High (Mixing/Baking/Cooling) |
| Texture | Creamy & Soft | Airy & Spongy |
| Make-Ahead | Mandatory (Needs to set) | Optional |
| Structure | Held by set custard | Held by flour/eggs |
Pro Tip for Serving
To achieve the professional-looking cross-section shown in the picture, use a sharp, thin-bladed knife dipped in hot water and wiped dry between every single cut. This prevents the custard from smearing and keeps the biscuit layers distinct
