In medium bowl, combine brown sugar, cinnamon, ginger, walnuts, macadamia nuts and bread crumbs; mix well and set aside.
In large bowl of electric mixer, cream together sugar, butter and vegetable shortening. Add eggs and vanilla and beat until light and fluffy.
Add flour, baking powder, salt and Herman; beat until smooth. Spoon half the batter into a well-greased and floured 9x13x2-inch baking pan.
Spoon half the reserved brown sugar mixture over the batter and sprinkle with pineapple. Smooth the remaining batter over the top and sprinkle with the remaining brown sugar mixture. Sprinkle with rum and pour melted butter over all.
Bake at 375° F for 25 to 30 minutes, until cake is puffed and browned. Cool several minutes before serving, but serve warm.Servings: 12 to 15