Ten second's inspiration, and twenty minute's work later, I'd saved the teacher a job.
Step 1: Materials and tools
- Mug - any old mug will do, preferably plastic in case of accidents.
- An old drink-can.
- Something sharp to cut the can.
- Some polystyrene packing (from under a frozen pizza).
- PVA glue.
- Cocoa powder.
- Something to stir the glue.
- Hot-glue gun.
Step 2: The Bulk of the Chocolate.
Make it tall enough to fill up at least half the mug, but short enough to prevent children's lips touching the chocolate too often when it's in use (to cut the risk of passing infections).
Be careful of the sharp edges.
Press the mug into the polystyrene to mark a circle for trimming. Cut out a disc that will fit snugly in the mug.
Use the hot-glue to tack the can into the mug (it wouldn't do for the hot chocolate to rattle and clang, would it?). Put a ring of hot-glue on top of the can, and then quickly press the disc into place, keeping it as level as you can.
Step 3: Make the Chocolate.
Pour a large blob of glue onto the polystyrene, and sprinkle on some cocoa powder. Stir it in with the stick. It takes quite a bit of stirring, and you may have to add a few drops of plain water to make it runnier, but eventually you will have a gooey, chocolate-coloured blob.
Pour the blob into the mug, onto the disc of polystyrene. You will need to spread the mixture, and burst a few bubbles, but you should be able to cover the polystyrene in a layer of "chocolate" that will settle into a nice smooth surface.
Before the glue dries, you will need to wipe up smudges and spills. I found a combination of damp fingers and damp tissue paper to be perfectly adequate for most of the mess, with dampened cotton-buds for the mess close to the edge of the chocoglue.
Leave the glue to dry overnight, and voila - a role-play prop fit for any classroom.