In a large bowl combine buttermilk, cream, granulated sugar, and vanilla. Stir until sugar dissolves. Freeze mixture in a 1-1/2- to 2-quart ice-cream freezer according to manufacturer's directions. Serve immediately or transfer ice cream to freezer container; cover and freeze up to 24 hours.

For topping, in a large skillet melt butter; whisk in brown sugar and water until sugar is dissolved and mixture is smooth.

To serve, scoop ice cream into bowls. Invert an ice cream cone on top of ice cream scoop. Top with sauce and sprinkle with caramel corn. Makes about 1-1/2 quarts (twelve 1/2-cup servings with 2 tablespoons sauce).

Double ingredients, using 2 quarts buttermilk, 2 cups whipping cream, 2 cups sugar, and 2 tablespoons vanilla for the recipe. Freeze according to manufacturer's directions. Ripen about 4 hours. (To ripen ice cream after churning, remove the lid and dasher. Cover top of freezer can with plastic wrap, waxed paper, or foil. Plug hole in lid with a piece of cloth; replace lid. Pack outer freezer bucket with enough ice and rock salt to cover top of freezer can, using 4 cups ice to 1 cup salt. Discard water from melted ice and replenish ice and salt as necessary.)