Process the separated chocolate wafers into fine crumbs, then pulse in 3 tablespoons of milk until the mixture gathers into a dough ball. The crumbs should bind together rather than remain loose, with no large cookie shards poking through.

Place the dough on plastic wrap, gather it with your hands, flatten it into a square, and use a rolling pin to make an even 1/4-inch layer before trimming the edges straight. Brief hand warmth helps the dough become pliable, and a consistent thickness reduces weak spots that can crack during rolling.

Stir the reserved cookie filling with 2 teaspoons of milk in a bowl until no stiff lumps remain. A soft frosting texture is the goal, loose enough to spread but thick enough to stay in place.

Cover the chocolate square with an even layer of the prepared filling. The cream should glide across the surface without pulling up crumbs or tearing the dough underneath.

Lift the plastic wrap to curl one edge inward, continue rolling into a snug log while peeling the wrap away, and optionally wrap and refrigerate it to firm up. A gently tightened roll holds the layers together without forcing the filling out at the seam.

Remove the plastic wrap and cut the log into rounds with a sharp knife, using a gentle sawing motion and wiping the blade between cuts. Clean cuts preserve the pale spiral, while downward pressure can flatten the soft chocolate layer.