Preheat oven to 400ºF. Spray an 8 x 8 baking dish with cooking spray; set aside.
In a large bowl, combine diced sweet potato (that has been slightly softened), black beans, tomatoes, onion, bell pepper, chili powder, garlic salt, and cinnamon.
Spread ½ cup salsa on the bottom of the baking dish. Arrange a tortilla on top, ripping into strips to get the right fit. Spoon a large layer of sweet potato/black bean mixture over tortilla strips. Spread the remaining ½ cup salsa over the sweet potato/black bean layer.
Add one more layer of tortillas and then add the rest of the sweet potato/black bean mixture over the tortilla layer. Top with cheese, if using.
Bake, uncovered, 20-25 minutes and until cheese is melted and top is slightly browned. Let stand 5 minutes. Cut into squares and serve. Top with additional salsa, cilantro, and/or avocado, if desired.
Overall verdict – just okay. I felt that it was overly soggy from the salsa and tomatoes. The sweet potatoes also need to be pretty much completely cooked before going into the oven. I personally don’t like cooking food in the microwave (besides for reheating leftovers) so I wasn’t a fan of that. I used a cilantro lime tortilla which worked well enough, but again, it was soggy from the salsa/tomatoes. If I were to make this again I would use fresh tomatoes rather than canned. I also used all of the optional garnishes, which I see as a must use. The cinnamon is slightly on the too much side (at least for me). I really liked the concept of this recipe, but I probably would not make it again. It might work better as a taco or burrito rather than a casserole.