We made ours by mixing 1.5 mugs of corn flour with 1 mug of water containing food colouring, to the consistency of a batter.
Everyone was very busy filling blancmange moulds ready to go into the freezer for 4 hours. We used blancmange moulds so the pretend ice cream would easily pop out by taking the bases off.
It started to melt just like real ice cream as we turned them out. It could be spooned, it could be dribbled, but as soon as it wasn't being manipulated it was firm.
The children were enthralled by the changing properties of the ice cream, especially on their hands. What looked like liquid could be scraped off fingers like a solid.
We had great fun setting up an ice cream parlour to sell our treats, adding a till, money, paper, pens and scissors to make price tickets for the wonderful flavours the children had thought of.