Meanwhile, place
large cast iron skillet (or nonstick but cast iron is best for texture and flavor in this instance) on stovetop over medium-high heat. Allow skillet to warm before adding chopped bacon. Cook bacon until crisp, then add chopped apples and rosemary. Continue cooking bacon with apples over medium heat until apples are just about soft, about 4-5 minutes.
Careful not to overcook the apples.