| 1 | For cake: position rack in top third of oven; preheat to 350-°F. |
| 2 | Butter two 9-inch-diameter cake pans with 1-?inch-high sides. |
| 3 | Line bottoms with waxed paper rounds. |
| 4 | Butter and flour paper. |
| 5 | Sift flour, baking powder and salt into medium bowl. |
| 6 | Using electric mixer, beat butter in large bowl until fluffy. |
| 7 | Gradually add sugar and beat 2 minutes. |
| 8 | Add eggs 1 at a time, beating well after each addition. |
| 9 | Beat in dark rum and vanilla extract. |
| 10 | Combine sour cream and baking soda in medium bowl. |
| 11 | Add mashed bananas to sour cream mixture and stir until well blended. |
| 12 | Add dry ingredients to butter mixture alternately with banana mixture, beginning and ending with dry ingredients. |
| 13 | Stir in chopped butterfinger bars. |
| 14 | Divide batter between prepared pans. |
| 15 | Bake until center of cake feels firm and tester inserted into center comes out clean, about 30 minutes. |
| 16 | Cool in pans on rack 10 minutes. |
| 17 | Run small knife around sides of cakes to loosen. |
| 18 | Turn out cakes onto racks and cook. |
| 19 | Peel off waxed paper. |
| 20 | (can be prepared 1 day ahead. |
| 21 | Wrap cakes tightly and store at room temperature). |
| 22 | For glaze: combine cream, butter and corn syrup in heavy medium saucepan. |
| 23 | Bring to simmer over medium heat, stirring unti butter melts. |
| 24 | Remove from heat; add chocolate and stir until melted and smooth. |
| 25 | Stir in rum and vanilla. |
| 26 | Pour glaze into small bowl. |
| 27 | Cover and refrigerate just until cool and thick, stirring occasionally, about 40 minutes. |
| 28 | Transfer 1 cake layer to platter. |
| 29 | Slide waxed paper strips under edges of cake. |
| 30 | Stir glaze until smooth. |
| 31 | Spread 1 cup glaze evenly over top of cake layer. |
| 32 | Top with second cake layer. |
| 33 | Spread remaining glaze over top and sides of cake. |
| 34 | Cover top and sides of cake with chopped butterfinger bars. |
| 35 | Remove paper strips. |
| 36 | (can be made 2 days ahead. |
| 37 | Cover cake and store at room temperature). |
