1. preheat oven to 425
2. combine spinach and ricotta cheese in a small bowl, in a separate bowl combine beans
3. Cut 3 corn tortillas into pieces and arrange in a solid layer to cover the bottom of an 8 inch square baking dish coated with cooking spray. Top with half each of beans, salsa, spinach mixture, and cheese. Repeat layers with remaining ingredients.
4. cover and bake at 425 for 25 minutes. Uncover and bake an additional 15 minutes or until bubbly and lightly browned. Let stand 10 minutes before serving.