- Combine both the sugars, corn syrup and Half-and-Half cream in a saucepan. Cook over low heat until boiling.
- Add cocoa and stirring as little as possible, bring to the soft ball stage (238 F).
- Add butter and vanilla extract without stirring. Cool to be at room temperature.
- Beat vigorously until thick. Pour into fudge mold and cool it until firm.
- Cut into bars and serve chilled.