Preheat oven to 350 degrees and butter and flour 3 (9-inch) round cake pans.
In a large bowl, combine butter and sugar and beat at medium speed with an electric mixer until fluffy.
Add eggs one at a time, beating well after each addition, and stopping to scrape down sides of the bowl. Beat in vanilla.
In a medium bowl, combine flour, baking powder, cinnamon, and salt.
Add flour mixture to butter mixture, alternating with milk, beginning and ending with flour mixture.
Pour batter into prepared pans. Bake 25 to 35 minutes or until top of the cake feels firm when gently pressed on. Let cakes cool 10 minutes. Remove from pans and place on wire racks to cool completely.
For icing, combine dark brown sugar, whipping cream, and 2 tablespoons butter in a small saucepan over medium heat. Cook for 3 to 4 minutes stirring constantly to dissolve the sugar. Let cool completely.
Using an electric mixer, beat remaining 1 1/2 cups butter and cream cheese at medium speed until smooth. Add brown sugar mixture and vanilla and beat to combine. Gradually add in confectioners' sugar, beating until smooth.
Spread icing between layers and cover top and sides.
For topping, melt butter over low heat in a medium skillet. Add brown sugar and cinnamon and cook for 3 to 4 minutes, stirring continuously.
Turn heat up to medium and add rum and liqueur and salt. Cook for 5 minutes, stirring frequently. Add bananas and pecans and cook for 1 minute. Let cool before spooning over top of cake.