Help modeling this dome I am very new to blender and still using 2.78, I have this idea in my head and but can't think of how to model a dome shape with a cross on top if that makes sense. I attached a sketch of how I want it to be, sorry if it is hard to understand. I don't care a lot about size or measurements.
I've tried this. It's made with bevels, mirror, extrusions, join and knife. I corrected the final extrusion as, as Lemon has pointed out, it looks like I inverted the cross.