Preheat the oven to 350 degrees F (175 degrees C). Grease a 2-quart casserole dish.

Bring a large pot of salted water to a boil. Cook cabbage in boiling water until barely tender, about 10 minutes; drain.

Meanwhile, melt butter in a small saucepan over low heat. Blend in flour, salt, and milk. Cook and stir until slightly thickened, then fold in cheese.

Transfer cabbage to the prepared casserole dish; stir in cheese sauce. Sprinkle cracker crumbs on top.

Bake in the preheated oven until top is browned, 25 to 30 minutes.