Before you start, preheat oven to 220°C (or 200°C fan bake). Set aside two lined oven trays.
Prep onion. Drain jackfruit and tear into small chunks. Using your hands, squeeze as much liquid out of the jackfruit as possible.
Heat oil in a large fry-pan on medium-high heat. Cook jackfruit and onion for 5-6 minutes, until softened. Add Mexican spices and cook for a further 1 minutes, stirring, until fragrant. Remove pan from heat and stir through BBQ sauce. Season to taste with salt.
Lay two tortillas on each oven tray. Divide refried beans between each tortilla and spread out evenly. Top with spinach and spread over jackfruit (reserve pan). Place remaining tortillas on top and press down lightly to stick.
Drizzle quesadillas with oil and bake for about 15 minutes, until golden.
Prep avocado and spring onion and place in a medium bowl. Wipe reserved pan clean and heat oil on high heat. Cook corn with a pinch of salt for 4-5 minutes, until tender and lightly charred. Transfer corn to bowl with avocado and spring onion. Add tomatillo sauce and toss to combine. Season to taste with salt and pepper.
To finish, cut each quesadilla into wedges. Prep coriander.
Serve quesadillas topped with garlic lime mayo, salsa, coriander and spicy pepitas.