Any recipes for two 7 year old boys to cook and keep entertained?

[daisycat01]

I have my sons friend coming round tomorow to play for a few hours. We thought it would be nice to do some cooking. I was hoping to find some ideas of what they could cook. I was thinking brownies or cakes...
Needs to be quite simple

TIA

Choocy krispies white choc and milk brown - ¾ white ¼ brown and mould into eyeballs!