This is a fun project we did last weekend. It was easy and had a great payoff!
You really can make ice cream using a few ingredients and a couple of plastic zip baggies.
Start by mixing 1/2 cup milk, 1/2 cream, 1/4 cup sugar, and 1/4 teaspoon vanilla in a zip lock quart sized baggie. Seal it well. In a gallon sized baggie, place 2-4 cups of ice and a cup or so of rock salt. Place the quart baggie inside the gallon baggie and seal well. Squish and sqeeze the ingredients for about 15 minutes until you have thick, creamy ice cream. It is a good idea to use a towel around the baggie as it gets very cold, actually cold enough to damage the skin.
This is a great activity and can even be used as a science lesson.