Combine sugar, salt, bay leaves, orange zest, peppercorns, rosemary, and 4 cups water in a medium saucepan. Bring to a boil, stirring until sugar and salt are dissolved. Reduce to a simmer and cook 1 minute. Remove from heat; let cool completely. Pour over pork chops in a 9-by-13-inch baking dish. Cover and refrigerate, turning once, at least 4 hours and up to overnight.
Remove pork from brine; discard brine. Pat chops dry; let stand 15 minutes. Heat a large cast-iron or other heavy skillet over medium-high heat. Add oil and swirl to coat. Add pork, working in batches, if necessary, and cook until bottoms are deep golden brown, about 5 minutes. Turn and cook until a thermometer inserted into thickest part of chops (without touching bone) registers 138 degrees, about 3 minutes more. Let rest 5 minutes. Garnish with parsley and serve with applesauce.