Sarcastic term for giving someone unnecessary recognition. Similar to a pat on the head or back. From the younger Girl Scouts called Brownies that are given buttons or badges for good deeds or accomplishments.
Calm down John...I'll give you a Brownie Button for not punching that rude old lady in the face for giving you the finger!
When your shit comes out like brownie batter and is usually smeared all over your butt cheeks. After the initial ten wipes it becomes very apparent when you have brownie butt. Typically taking several trips to the bathroom throughout the day to be fully cleaned.