I recently tried Cakeman Ravens Red Velvet Cake and it was not good. The cake sunk in the middle and was dense. It also had a bitter taste to it. I think I may have added too much red food coloring but the recipe called for 2 tablespoons. I was wondering if anybody else has had this problem? This is my first scratch cake and Im baking at 7000 feet, so I know that has something to do with it. I just dont know how to fix it. Any thoughts?