Steps
1. In a small saucepan, heat the milk and heavy cream over medium heat until warm.
2. Add the sugar, vanilla extract, cocoa powder, and salt, whisking until fully combined.
3. Break the digestive biscuits into smaller pieces and layer them in a serving dish.
4. Pour the warm custard mixture over the biscuits, ensuring they are soaked well.
5. Let it rest for about 10 minutes to allow the biscuits to absorb the custard.
6. Garnish with chocolate shavings before serving.