Mama smothers pork chops in cola soda in casserole. This recipe is to die for

4 bone-in pork chops, about 3/4 to 1 inch thick
1 teaspoon salt
1/2 teaspoon black pepper
1 teaspoon garlic powder
1 teaspoon onion powder
1/2 cup all-purpose flour (for dredging, plus 1 tablespoon reserved)
2 tablespoons vegetable oil or bacon drippings
1 large yellow onion, thinly sliced
2 cloves garlic, minced (optional but nice)
1 can (12 ounces) cola soda (not diet)
1/2 cup low-sodium chicken broth or water
1 tablespoon Worcestershire sauce
1 tablespoon ketchup or tomato paste
1 teaspoon dried thyme or 1 tablespoon fresh thyme leaves (optional)
1 bay leaf (optional)
2 tablespoons butter
Chopped fresh parsley for garnish (optional)