Help - icing for chocolate cake (without icing sugar or real chocolate!)

[PhoebeMcPeePee]

I've made a chocolate cake & about to do my T&T buttercream icing on top but I've run out of icing sugar & haven't got any proper chocolate so a bit stumped what to put in top.
I'm thinking I could possibly do a fudge type icing with sugar, cocoa, butter & milk but no idea in reality if this will work or quantities needed. Has anyone got any suggestions?

really

Nutella?

I use this one and it is brilliant.

Like the sound of the fudge one will give that a go (& for the blender tip that's fab)

Not my night for baking clearly - it's very runny blueb how long should I boil it for?

Have you got natural yoghurt? Mixed with melted chocolate it goes fudgy and is just a little bit bitter which is delicious with the sweet sponge.

I took it off the heat & after a good beating it's gone thicker but still pourable so job done & thank you ever so much