Yes, it can (Conversion tables found online.) But a slow cooker will not produce any crispy skin. Cook as directed, pull out chicken thighs, then pat dry and cook or broil on high heat careful not to overcook the meat. Oce crisp, plate with slower cooker remains.
What if I brown the chicken before I put it on crockpot. Can everything else, like the spinach and cream go in for five hours?
I'd probably wait to add the cream and spinach until the last 30 minutes or so. Slow cookers retain much more moisture than dry heat cooking methods, and you're going to get a lot of moisture from the fresh spinach. So, I'd consider skipping the chicken broth, and just letting the chicken cook in its own juices. It really just depends on how much "sauce" you want.