Preheat oven to 500 degrees. Butter a large shallow baking dish, and sprinkle with 1 tablespoon sugar; set aside.
Peel, and cut bananas diagonally into 1/2-inch slices. Add bananas to prepared dish, and sprinkle with remaining 2 tablespoons sugar, cardamom, and salt. Dot with butter. Drizzle with lemon juice.
Bake until bubbling, about 8 minutes. Serve with ice cream.