One version of the recipe I printed out said 5 minutes -- but the topping was already beginning to burn after 3 minutes on broil. I also found there was a lot of topping.
What a "timely" question! I made some yesterday. and
five minutes under the broiler will set off the fire alarms. I never take my eyes off the oven when this banana bread is finishing because the pecans advance to the charcoal stage in seconds if you aren't watching them!