Preheat your oven to 375°F (190°C). Chop the onion, mince the garlic, and chop turkey bacon into bite-sized pieces. Cook rice if not already cooked.
In a large skillet over medium heat, cook the turkey bacon until crispy, about 5-7 minutes. Transfer to a paper towel-lined plate to drain excess fat, leaving some bacon grease in the pan.
Add diced onion to the skillet with bacon grease and sauté until translucent, about 3-4 minutes. Add minced garlic and cook for 30 seconds until fragrant.
Add ground beef to the skillet with onions and garlic. Break up with a spoon and cook until no longer pink, about 7-8 minutes. Season with salt, pepper, chili powder, and cumin.
Add drained black beans, corn kernels, and the entire can of diced tomatoes with juices to the skillet. Stir and simmer for 5 minutes to meld flavors.
In a large mixing bowl, combine the cooked beef mixture, cooked rice, half of the shredded cheddar cheese, and crispy turkey bacon. Mix evenly. Transfer to a greased 9x13-inch casserole dish and spread out.
Sprinkle the remaining cheddar cheese evenly over the casserole. Bake in the preheated oven for 20-25 minutes until cheese is melted and bubbly.
Let casserole sit for 5 minutes after baking. Dollop sour cream on top and sprinkle with fresh cilantro before serving.