Preheat oven to 375 degrees. Prepare a mini loaf tin with PAM Spray Pumps in Canola Oil. Set aside.
2. In a large bowl, mix together the bananas, butter, vanilla, brown sugar, eggs, and sour cream until smooth. You can do this by hand with a whisk or with a hand mixer. If using a hand mixer be careful, this mixture will be loose. Set aside.
3. In a medium sized bowl, mix together the baking soda, salt, flour, and cocoa powder. Slowly fold in the dry ingredients into the wet until just combined and there are no dry patches.
4. Pour the mixture about 1/2 inch up the sides of the mini loaf tin. This recipe makes 10 loaves. Press in two chocolate sandwich cookies, these might have to slightly over lap. Top with the remaining banana bread batter evenly.
5. Bake for 18-23 minutes, until a toothpick inserted into the center comes out mostly clean. Place tin on a wired rack and let cool for 10 minutes. Take out the banana bread loaves and place on the wired rack directly. Let cool completely.