To heat the oven, select the Convection mode and set the temperature to 325° F. Butter and flour a 9x5x2½" loaf pan and set aside.
Combine the flour, baking soda, baking powder and salt in a large mixing bowl.
Combine the chocolate chips and nuts and toss with 1 tsp of flour and set aside.
Beat the butter and sugar until light and fluffy in a stand mixer or by hand. Add the eggs one at a time, mixing gently to combine, then stir in the bananas and vanilla.
Beat in the flour mixture and finally fold in the chocolate chips.
Scrape the batter into the prepared pan, smooth the top and place the pan in the oven on rack position 2 counting up from the bottom. Set the timer for 25 minutes.
When the timer elapses, change the oven mode to Bottom Heat and increase the temperature to 350° F. Set the timer for 20 minutes and check the bread with a tester. If the tester comes out clean remove the bread from the oven otherwise continue baking for an additional 5 minutes.
Cool the pan on a rack for an hour before turning the bread out of the pan onto the rack to continue cooling.
