In a medium saucepan, stir together half-and-half, cake mix and sugar. Gently heat and stir until mixture just bubbles. Pour mixture into a large heatproof mixing bowl and whisk briskly. Cover and cool for 1 hour. Stir in whipping cream and vanilla. Cover the bowl with plastic wrap then chill in the refrigerator for at least 2 hours or until the mixture is well chilled.

When mixture is well chilled, pour into a 1-1/2-quart ice cream freezer and freeze according the manufacturer's instructions. Transfer to a freezer container and freeze overnight to ripen. Makes 5 cups.

Prepare as directed above; pour the mixture into an ice cream freezer. Freeze according the manufacturer's instructions. Stir 2 tablespoons colored sprinkles and, if you like, stir 1/2 cup miniature chocolate pieces, chopped nuts and/or coarsely chopped maraschino cherries into the ice cream mixture before freezing overnight to ripen.

Prepare as directed above, except substitute 1 package 1-layer chocolate cake mix for white cake mix. Pour the mixture into an ice cream freezer. Freeze according the manufacturer's instructions. Stir 2/3 cup miniature chocolate pieces into the ice cream mixture before freezing overnight to ripen.