Preheat oven to 350 degrees F. Lightly grease a 9-inch square by 2-inch deep baking pan; set aside. In a medium saucepan, combine chocolate, butter, and the water; cook and stir over low heat until chocolate is melted. Transfer to a large bowl.
Add granulated sugar and brown sugar to chocolate mixture; beat with an electric mixer on low to medium speed until combined. Add eggs and vanilla; beat on medium speed for 2 minutes. Add flour, salt, and cinnamon. Beat on low speed until combined. Spread batter in prepared pan.
Bake for 25 to 30 minutes or until a toothpick inserted near center comes out clean. Cool in pan on a wire rack. Cut into bars. Sprinkle with cocoa powder and/or powdered sugar.
Makes: 20 to 25 brownies
To Bake Ahead: Prepare brownies as directed; do not cut into bars. Cover pan. Store at room temperature for up to 3 days. For longer storage, cut brownies into bars and layer between waxed paper in an airtight container; cover. Freeze for up to 3 months. Thaw brownies; sprinkle with cocoa powder and/or powdered sugar.