I made them too, and nobody noticed until I said something. I also added a little vanilla just to make sure there was no beany taste.
I did notice a few things about them though:
1) when they are hot out of the oven, you don't taste the beans.
2) when you eat one cold, you can't taste the beans.
3) when you reheat the brownies when they are cold, you kind of taste the beans. Good luck!