Combine the chocolate chips, pecans, sugar, and cinnamon.
Set aside.
To make the cake:
Preheat oven to 350°F (175°C). Grease a 12-cup Bundt pan or tube pan with a fixed bottom.
Whisk together the flour, baking powder, cinnamon, baking soda, and salt. Set aside.
Using an electric mixer on medium speed, beat the butter, sugar, and brown sugar until light and fluffy. Add the eggs, one at a time, mixing well after each addition. Add the bananas and sour cream, and mix until combined.
Reduce mixer speed to low. Gradually add the flour mixture, mixing just until combined.
Sprinkle about a third of the chocolate-nut mixture on the bottom of prepared pan. Drop half of the cake batter by spoonfuls into the pan. Sprinkle with half of the remaining chocolate-nut mixture. Top with the remaining cake batter. Sprinkle with the remaining chocolate-nut mixture.
Bake 45 to 50 minutes, or until a pick inserted into the center comes out clean.
Cool the cake in the pan on a wire rack for 15 minutes. Then, invert the cake onto a wire rack, and invert again onto a cake plate for serving.
Notes
Store in an airtight container at room temperature up to 3 days.
For tips, step-by-step photos, and extra details, be sure to read the full post above before starting. It’s packed with helpful info to answer common questions!