Prepare cake mix according to package directions,(the 1 1/3 cup water, 3 T. oil, 3 large eggs, adding mashed bananas and ginger to the mix. Pour mixture into a lightly greased and floured 13 X 9 inch pan.
Bake at 350 degrees for 35 to 40 minutes or until a wooden pick inserted in center comes out clean. Brush cake with 1/4 cup rum. Cool in pan 20 minutes. Crumble into 2 inch chunks.
Melt butter in a large skillet over medium-high heat; add dark brown sugar and cinnamon, and cook 1 minute. Add sliced bananas, and cook, stirring constrantly, 2 to 3 minutes or until bananas are tender. Remove from heat, and pour remaining 1/4 cup rum over banana mixture. Pour mixture into a large bowl. Let cool 15 minutes. Cover and chill 1 hour.
Prepare pudding mix as directed, using 2 cups milk; stir into banana mixture. Cover and chill 2 hours.
Place half of banana cake chunks in a large trifle dish. Spread half of pudding mixture over cake. Top with half of Cream Cheese Topping. Repeat layers once. Sprinkle with grated chocolate.
To make Cream Cheese Topping:.
Beat first 3 ingredients at medium speed with an electric mixture until smooth. Stir in whipped topping until well blended.