Add the half-and-half, sugar and vanilla extract to the quart-size zip-top bag. Press out as much excess air as possible, then seal the bag tightly. Gently squeeze the bag a few times to help mix the ingredients together.

Fill the gallon-size bag about halfway with ice. Sprinkle the ice cream salt evenly over the ice.

Place the sealed quart-size bag inside the gallon bag, making sure it is surrounded by the ice and salt mixture. Seal the gallon bag tightly.

Shake the bag continuously for about 5–10 minutes, or until the half-and-half mixture thickens and reaches an ice cream consistency.

The outside bag will get very cold, so kids may want to wear gloves or wrap the bag in a kitchen towel while shaking.

Remove the smaller bag from the ice mixture and quickly rinse or wipe off the outside to remove any salt. Open the bag, grab a spoon and enjoy your homemade ice cream!