How to Make It
Sift together the cocoa, sugar, flour, and salt into a large skillet.
Whisking continuously, add the warm milk in a slow, steady stream and whisk until smooth.
Cook over medium heat, stirring continuously with a heatproof spatula until the gravy thickly coats it, about 8 minutes.
Remove the skillet from the heat, add the butter, and stir until melted.
To serve: Split the hot biscuits in half and divide among serving plates. Top with warm gravy and serve straightaway.