Ingredients

• 1/2 cup granulated sugar
• 1/3 cup unsalted butter, softened
• 1 large egg
• 1/3 cup buttermilk
• 1/2 teaspoon vanilla extract
• 3/4 cup all-purpose flour
• 1/2 cup rye flour
• 1/2 teaspoon baking soda
• 1/2 teaspoon kosher salt
• 3 1/2 ounces dark chocolate, chopped (about 1/2 cup)
• 1 tablespoon light corn syrup
• 3 1/2 ounces ruby chocolate or white chocolate, chopped (about 1/2 cup)
• pinch of salt
• 1 cup heavy cream