Melt butter, brown sugar and cinnamon over medium heat until the sugar begins to dissolve and become smooth. Add rum and cook 1 minute more. Divide evenly between 2 well-greased nine inch cake pans. Arrange banana slices in circles over the caramel.
Heat oven to 350*.
Cream sugar and butter on medium speed until very light and fluffy--about 10 minutes. Add eggs one at a time, beating well after each addition. Add vanilla and rum extracts.
Stir together flour, baking powder, baking soda, salt and cinnamon.
At low speed, beat in flour in 3 parts alternating with the sour cream, beginning and ending with the flour.
Spoon gently over bananas and spread to even the surface out. Bake 45-55 minutes til a toothpick inserted into the center comes out clean. Cool in the pan on a wire rack for 15 minutes, then carefully invert onto the wire rack to finish cooling.
Meanwhile, beat cream cheese and butter until very smooth. Beat in brown sugar and beat til smooth. Add rum, vanilla and cinnamon, then add powdered sugar to achieve spreading consistency and continue beating until smooth.
When cakes are completely cool, carefully, CAREFULLY place one layer on your cake plate. Top with a bit of your frosting, then carefully put the top layer on. Frost only the sides of the cake and leave the pretty little bananas peeking out on top.