Reply to Re-inforcing an expedit?

Im going to put it together with liquid nails, But what is the best way to attach wood to it i want to put the typical shelf on top and cut it out to make my mixer sit flush, Ive seen pictures of the inside of the wood (its like honeycomb) is it safe to screw plywood onto the back of it and screw the shelf on? or would it be better to attach it with expandable screw or something like that?