1. Preheat to 325 degrees F. Line 3 baking sheets with parchment and set aside.
2. Place butter and unsweetened and semisweet chocolate in a large heatproof bowl. Bring a saucepan filled with about 1 inch of water to a very slow simmer; set bowl over but not touching water, and stir occasionally until chocolate melts. Stir light brown and granulated sugars and vanilla into chocolate mixture with a wooden spoon. Add eggs and buttermilk and beat vigorously until thick and glossy.
3. Whisk flour, cocoa, cinnamon, and salt together and stir into chocolate mixture. Stir in chocolate chunks and dried cherries, if using. Drop batter in heaping tablespoons, 2 inches apart, onto prepared baking sheets. Bake until cookies are set on outside and soft and fudge-like inside, 12 to 15 minutes. Cool cookies on baking sheet for 5 minutes; transfer to a rack to cool completely. Serve or store cookies in a tightly sealed container at room temperature for up to a week.
Copyright 2009 Television Food Network, G.P. All rights reserved