Note: If you can't find Moxie, substitute cola, root beer, or Dr Pepper. May be frozen.
1. Preheat the oven to 350 degrees F. Grease and flour a 9-by-13 baking pan.
2. Whisk flour, baking soda, and salt together in a large mixing bowl. Set aside.
3. In a large saucepan, combine Moxie and butter and heat over medium heat until butter is melted and the mixture is warm. Remove from heat and whisk in the cocoa, then both the sugars. Stir in the sour cream, eggs, and vanilla. Whisk until smooth.
4. Pour Moxie mixture into the flour mixture and stir vigorously with a wooden spoon until smooth, about 2 minutes. Pour batter into prepared baking pan. Sprinkle chocolate chips over the surface.
5. Bake for 40 to 45 minutes, until a cake tester comes out clean. Cool cake in pan for 1 hour. Cut into 20 pieces and serve from the pan. Store, covered, at room temperature or refrigerated.
Source: fresh magazine July, August 2010