Warm half of the butter in a skillet until the foam reduces, then add bananas with the cut side down. Cook about 2-3 minutes then flip and cook other side. Place 2 slices of banana each into four serving bowls. Melt the remaining butter in the skillet, then add brown sugar, cardamom, and salt. Whisk in the cream. Simmer until slightly thickened, about 3 minutes. Remove from heat and stir in the lime juice. Drizzle sauce evenly over warm bananas. Serve immediately.