Pour melted margarine into 9 x 13" pan. Combine brown sugar and cinnamon and sprinkle evenly over margarine. Lay 2 layers (6 slices each) of bread on top of brown sugar mixture. Beat together eggs and milk. Pour over bread. Cover and refrigerate overnight. Next morning uncover and bake for 30 minutes at 350 degrees. Serve immediately. Makes its own syrup. ENJOY!