Chocolate Biscuit Pudding

Method

1. Heat 80 ml of milk in a small saucepan or in the microwave until just warm, stir in 0.5 tsp of instant coffee powder until fully dissolved, and pour into a shallow bowl wide enough to dip a biscuit. Leave to cool to room temperature — hot milk will collapse the biscuits.
2. Melt 15 g of butter in a small heavy pan over the lowest heat. Sift in 8 g of cocoa powder and whisk for 1 minute until it smells toasty and looks like wet sand, keeping the heat gentle so the cocoa does not scorch.
3. Whisk in 30 g of icing sugar and 60 ml of milk in a steady stream, raise to a bare simmer and cook 3-4 minutes, whisking constantly, until the sauce thickly coats the back of a spoon and a drawn line holds for a second. Off the heat, stir in 0.25 tsp of vanilla essence and a pinch of salt, then let it cool for about 10 minutes until warm but still spreadable.
4. Dip 4 Marie biscuits one at a time into the coffee milk, no more than a second a side so they stay firm, and arrange them in a single tight layer in a small dish of about 12 cm, snapping biscuits to fill the gaps.