Use-up-the-bananas Brownies

In our house, bananas are popular – but it’s not uncommon to end up with two or three very sad looking bananas at the end of the week. What to do, what to do…
This is kind of a cheat, but at least it’s an alternative to yet another loaf of banana bread.
2 or 3 sad bananas
1 pkge brownie or cake mix
oil and eggs as per the cake mix instructions (if it calls for 3 eggs, use 2)
1 cup walnuts/choc chips/raisins
Use the food processor to mash the bananas, adding the oil and eggs. Once the banana mash is uniform, mix it into the dry cake mix, adding the nuts or alternative at the end.
Bake according to the cake mix instructions – mine took 25 minutes for a 9″ pan.
I plan on experimenting with this one, not least because I happen to have a box of white cake mix in the cupboard. I think it’s probably possible to add things like oats, but time will tell.
In the meantime, tell me – what do you do with your sad bananas?