Preheat oven to 350°. Bake pecans in a single layer 8 to 10 minutes or until toasted and fragrant, stirring once.
Melt ¼ cup butter in a 10 inch cast iron skillet or a 9 inch round cake pan over low heat.
Remove from heat; stir in brown sugar and rum.
Cut bananas diagonally into ¼ inch thick slices; arrange over brown sugar mixture.
Sprinkle pecans over bananas.
Beat sugar and remaining butter at medium speed with an electric mixer until blended.
Add eggs, 1 at a time, beating until just blended after each addition.
Add milk and next 2 ingredients; beat just until blended after each addition.
Beat in baking mix and cinnamon until blended. (Batter will be lumpy).
Pour batter over mixture in skillet. Place skillet on a foil-lined baking tray.
Bake 350° for 40 to 45 minutes or until a toothpick inserted in the center comes out clean.
Cool in skillet on a wire rack 10 minutes. Run a knife around edge to loosen.
Invert onto serving plate, spoon any topping in skillet over cake.
Serve with whipped cream and/or ice cream.