Carefully transfer the calzone to the prepared baking sheet (here's an affiliate link similar to the bench scraper
I like to use), then use a sharp knife to cut about 5 slits in the top. Brush the top with olive oil and sprinkle with salt. Bake 15-20 minutes, until the dough is crisp and the filling is hot and melted. Let rest 5 minutes before cutting and serving with warmed marinara sauce for dipping.