In a small bowl, whisk together the whipping cream and corn starch; set aside. Add the butter to a saucepan over medium heat. Melt the butter and let it heat until it starts getting foamy, swirling the pan occasionally. After the foam subsides, continue to cook until you have brown bits forming. Decrease the heat to low and quickly stir in the whipping cream/corn starch mixture, corn syrup, brown sugar and vanilla beans (halved and scraped). Increase the heat to medium and stir until it’s bubbly and thickened a bit. Makes 3 cups.
Note: The sauce will thicken as it cools; reheat if needed.