Preheat oven to 350°F. Line a 9-by-5-inch loaf pan with foil, leaving 3 inches of overhang on both long sides. Lightly mist with cooking spray.
In a large bowl, using your hands, gently mix all ingredients until just combined. Pat mixture into prepared pan, scraping sides of bowl with a rubber spatula if necessary; smooth top.
Bake until internal temperature registers 165°F on an instant-read thermometer, about 1 hour. Let rest 10 minutes. Using foil overhang as handles, carefully lift meat loaf out of pan. Place meat loaf on a cutting board, peel back foil and slice. Serve hot with extra salsa, if desired.