Preheat the oven to 350 degrees F (175 degrees C).
Heat a large skillet over medium-high heat. Cook and stir beef in the hot skillet until browned and crumbly, 5 to 7 minutes. Drain and discard grease. Add cabbage, onion, salt, and pepper; mix well.
Cover the bottom of a 9x13-inch baking pan with 1 package of crescent rolls. Pinch seams together. Pour beef-cabbage mixture over the dough. Spread undiluted mushroom soup on top. Cover with mozzarella cheese. Unroll the second package of crescent roll dough over the filling.
Bake in the preheated oven until top and edges are golden brown, about 30 minutes.
