Step 1

For the gravy: In a stockpot set over low heat, add half of the milk, the sugar, all-purpose flour and cocoa powder, and bring to a light boil stirring constantly. Cook for at least 40 minutes. Add more milk a little bit at a time as necessary to reach a thick, saucy consistency.

Step 2

For the biscuits: Preheat the oven to 475 degrees F. In large mixing bowl, add the pastry flour. Using a large-hole box grater, grate the frozen butter into the flour. Toss to distribute evenly. Make a well in the center and pour the buttermilk into the well. Slowly incorporate the buttermilk into the flour using your hands. Kneed until dough-like, 15 to 20 times.

Step 3

Lightly flour a work surface and rolling pin. Place the dough on the floured surface and roll out to 3/4-inch-thick round. Fold the dough back onto itself. Repeat the rolling and folding three more times, then roll out the dough to 1/2-inch thick. Cut with a small biscuit cutter and place on a sheet pan lined with parchment paper. Bake until golden brown, 15 to 18 minutes.

Step 4

Brush the hot biscuits with warm melted butter. Split the biscuits in half and pour the warm cocoa gravy over top and sprinkle with confectioners' sugar. Serve warm.