Butter a 9x13 inch pan. Set aside.

Split vanilla bean pods and scrape out the inside pulp. Keep pods for another use.

In a large heavy-bottomed saucepan over medium high heat, combine corn syrup, sugar, butter, and 1 cup of cream.

Bring to a boil, stirring to dissolve sugar. Insert a candy thermometer and cook, stirring continuously, until the temperature reaches 244°F.

Remove from heat and, while stirring, slowly add remaining cream. Return to heat and cook until the temperature again reaches 244°F.

Remove from heat, stir in vanilla pod scrapings, pour into buttered pan, and let cool completely.

Invert pan over waxed paper to remove, sprinkle lightly with salt, cut into 1-inch squares, and wrap in pieces of waxed paper.