I gave Finn a bowl of left over noodles, and some food colouring. He had great fun mixing, stirring and pouring the noodles into muffin trays and other small containers.
It did get messy- so I recommend this for outdoor play, or putting a plastic mat down if it's a covered or indoor area.
If you add a bit of glue to the pasta, children can also arrange noodles and make patterns onto a piece of cardboard. Allow to dry.