1. Preheat oven to 350°F (175°C). Grease and flour a bundt pan.
2. In a bowl, whisk together flour, baking powder, and baking soda. Set aside.
3. In another bowl, beat softened butter, granulated sugar, and brown sugar until creamy. Add eggs, one at a time, followed by mashed bananas, sour cream, and vanilla extract.
4. Gradually add dry ingredients to the wet mixture, mixing until just combined. Fold in chopped pecans.
5. Pour the batter into the prepared bundt pan and bake for 50-55 minutes, or until a toothpick inserted into the center comes out clean. Cool completely before removing from the pan.
6. Drizzle the cake with warm caramel sauce and sprinkle additional pecans on top before serving.