Preheat the oven to 350 degrees F. Lightly coat the inside of a 2.5-quart casserole dish with non-stick cooking spray. Set aside.
Place a large deep-soded skillet over medium heat and add the butter. Once melted, add the cabbage and onion. Cook, stirring occasionally, for 5-8 minutes until the cabbage has softened, but is not fully cooked. Add the salt, garlic powder, and pepper, sitre, and cook for 1 more minute.
Transfer the cabbage to the prepared baking dish and spread it into an even layer.
In a small mixing bowl, whisk together the cream of mushroom soup and mayo. Spread this mixture evenly over the cabbage. Sprinkle the cheese all over the soup mixture.
In a medium mixing bowl, stir together the crushed crackers and melted butter until the crackers are moistened. Sprinkle evenly over the cheese.
Bake for 30 minutes or unitl gold brown. Remove from the oven and serve warm with your favorite meals.
Notes
You can use a 9x13 (3-quart) baking dish for this recipe if you don't have a 2.5-quart dish on hand.
I used regular Ritz crackers for the topping, and it was the perfect amount of salt with a bite of cabbage. I would not suggest a low-sodium cracker unless you very generously salt the cabbage or use salted butter and salt the cabbage to taste.