Preheat broiler. Coat baking sheet with cooking spray.
Combine beans, rice, corn, scallions and 1/3 cup of cilantro in medium bowl. Toss.
Place tortillas on work surface. Place 1 cup of bean mixture down center of 1 tortilla.
Fold in sides, then roll in tight cylinder. Place chimichanga seam side down on baking sheet. Repeat with remaining tortillas. Brush tortillas with oil.
Broil in center of oven 3 to 5 minutes, or until crisp and lightly brown.
Sprinkle with remaining cilantro. Serve with salsa and avocado.