Tex Mex Casserole

Combine refried beans, frozen corn, poblanos, 1/4 cup cilantro, the cumin and chile powder in a medium bowl. Combine the salsa, tomatoes, and the remaining 1/4 cup cilantro in a separate bowl. Toss the cheddar andmuenster cheese in a third bowl; set aside. Spread about 1/2 cup of the salsa mixture in a thin layer in a 6-quart slow cooker. Top with about 6 tostada shells, breaking them as needed to cover the bottom. Spread half of the bean mixture over the tostada shells, then sprinkle with 1 1/2 cups of the cheese mixture and 1 cup salsa mixture. Repeat the layers (tostada shells, bean mixture, cheese, salsa mixture), then top with the reamining tostadas, cheese, and salsa. Cover and cook on low 4 hours. Uncover and let rest 15 minutes. Serve with the avocados and sour cream