ISO: simple, basic coffee cake for 9×9 inch pan

Hi Folks,

I am looking for a simple, basic coffee cake recipe that can be easily varied by adding fruit, nuts, spices, cocoa or whatever that will fit in a 9×9″ pan.  Or if you have a great recipe for a chocolate, lemon, spice or any kind of fruit coffee cake, and are willing to share, I would be very pleased with that as well.

My son has finally showed an interest in learning to cook and bake, so I thought I’d start him off with something easy.

I look forward to see what you come up with.