3/4 cup sour cream
1/4 cup milk
2 tablespoons light corn syrup
2 tablespoons butter
2 cups granulated sugar
1 teaspoon vanilla extract
1/2 cup chopped walnut (optional)
1. Line a 8-inch square pan with lightly buttered waxed paper or aluminum foil. Set aside.
2. In a large, heavy saucepan combine sour cream, milk, syrup, butter and sugar and cook over medium low heat. Stir until the sugar dissolves, cover with a lid briefly to get any sugar crystals off the sides of the pan. Bring to a boil, stirring constantly, and cook to the soft ball stage (238*F / 115*C) or until a small amount dropped into cold water forms a soft ball that flattens when removed from the water. Remove from heat.
3. Let cool to room temperature, without stirring.
4. Add vanilla and beat with a heavy wooden spoon until it starts to thicken; add the walnuts and continue to beat until candy loses some of its gloss.
5. Spread evenly in the prepared pan. When firm, invert pan; peel off waxed paper and cut into small pieces. Store in an airtight container at room temperature.