Adjust the oven rack to the lower-middle position. Preheat the oven to 350 degrees. Grease the sides and bottom of a 9x5 loaf pan with cooking spray.
Spread the coconut on a baking sheet and place in the oven to toast, stirring every 2 minutes, until lightly golden brown and toasted, about 5-6 minutes. Remove from the oven and set aside.
In a large bowl, whisk together the flour, white sugar, baking soda, salt, and toasted coconut until well combined.
Mix the well-mashed bananas, sour cream, eggs, butter, and vanilla until very well combined.
Lightly fold the banana mixture and most of the chocolate chips into the flour mixture with a rubber spatula until just combined and the batter looks thick and chunky. Pour the batter into the loaf pan and top with remaining chocolate chips.
Bake for 45-55 minutes, or until a tester inserted in the center, comes out clean. Remove from the oven and allow to cool in the pan for 5 minutes, then transfer to a wire rack. Slice and serve warm or at room temperature.