What you'll need

• Ice cubes (enough to fill each gallon-size bag about half full)
• 1 cup half and half
• 1/2 cup salt (The bigger the granules, the better. Kosher or rock salt works best, but table salt is fine.)
• 2 tablespoons sugar
• 1/2 teaspoon vanilla extract
• 1 pint-size ziplock bag
• 1 gallon-size ziplock bag
• Your favorite mixins such as chocolate chips, cereal pieces, or fresh fruit.