Place a handful of flour in a bowl. Show your toddler how to stir the flour and how to transfer it to another bowl with a spoon. Then let them cook up their creation. Another variation is to put flour on a cookie sheet and show them how to draw things in the flour.
This activity is like a miracle in a bowl. I pull it out quite frequently while I'm cooking dinner and it keeps meltdowns to a minimum. So, Hurray for it.