Cut three 25x3-in. strips of heavy-duty foil; crisscross so they resemble spokes of a wheel. Place strips on the bottom and up the sides of a 5-qt. slow cooker. Coat strips with cooking spray., In a large saucepan, cook the vegetarian meat crumbles, onion and green pepper in oil until vegetables are tender. Stir in both cans of beans, tomatoes, water, chili powder, cumin and pepper. Bring to a boil. Reduce heat; simmer, uncovered, for 10 minutes., In prepared slow cooker, layer 1 cup bean mixture, 1 tortilla and 1/3 cup cheese. Repeat layers 5 times. Cover and cook on low until heated through and cheese is melted, 4-5 hours. (To avoid scorching, rotate slow cooker insert a half turn midway through cooking, lifting carefully with oven mitts.) , Using foil strips as handles, remove the pie to a platter. Serve with toppings of your choice.