In a small bowl, combine mixed nuts, dried cranberries, orange zest, cinnamon, and Cointreau. Spray a sheet pan with cooking spray.
In a saucepan over medium heat, combine the sugar, water, and juice and whisk until the sugar dissolves. Continue to boil until the mixture reaches 300 degrees. Do not stir or whisk, as this affects the sugar molecules. You may swirl the pan if you are worried about burning. This mixture is scalding hot, so use extreme caution.
Once the mixture reaches 300 degrees and appears to be an amber color, pour in the nuts and cranberries. Cook for one more minute and then transfer the mixture to the sprayed sheet pan. Use a spatula to quickly and lightly spread into an even layer. Let it cool completely to set. Break into pieces and enjoy!