The bottom layer is yellow cake and the top layer is ... the prepared pan when you add the cake mix bottom layer. Serve these Ooey Gooey Butter bars with a napkin or 3. They are definitely packed ...

It is hard to believe that it is made with a yellow cake mix ... the prepared pan when you add the cake mix bottom layer.

Spread over the cake mix layer. Bake bars for 45 minutes, or until edges are golden brown and the center has set to a soft consistency. Cool completely before slicing into bars and serving.