Preheat oven to 220°C. Place tortillas in a single layer on a baking tray; coat both sides of each one with cooking spray. Bake until lightly browned and crisp, about 10 minutes; turn them over halfway through. Transfer to wire racks to cool.
Combine beans, corn, tomato, onion, chilli, coriander, lime juice, salt and Tabasco in a large bowl. Gently fold in avocado. Top each tortilla evenly with bean mixture.