• Cookies:
  • 1 ounce bittersweet chocolate
  • 2 ounces semisweet chocolate
  • 1 cup unsalted butter, softened, plus a little extra for greasing the baking sheet
  • 1/2 cup granulated sugar
  • 2 cups all-purpose flour
  •  
  • Sauce:
  • 3/4 cup heavy cream
  • 8 ounces white chocolate, chopped or shaved into small pieces
  • 1/2 cup sour cream, preferably at room temperature

Preheat the oven to 350 degrees F. In a small metal bowl, combine the 2 types of chocolate and melt them gently over a pot of simmering water or a double boiler. Cool chocolate to room temperature.