How about I take the title literally? The sweetest revenge?

There was a bakery I used to go to during college. It was owned by a very nice guy who I could geek out about video games and movies. And his baked goods were some of the best I’ve ever had. This guy could make a 3D cake of the Doctor Who’s TARDIS and it’d taste amazing.
I made it a habit to stop by before doing my shopping on Saturday. Most of the time I was the first customer of the day. I’d buy 1 or 2 (or 3 for a special occasion) sugar cookies and talk to the baker as he worked. And these cookies were the best! Cute designs, bright colors in carefully decorated frosting, tasted like heaven.

After a couple months, I came to the store a little later than my usual time. There was someone talking angrily to the baker; a frequent customer. The days he came to the store were random and 2 times a week but lately he picked more Saturdays. I never saw him but I have heard of him.
This stranger was furious that I would come in before him and order the cookies first. How dare this baker sell these cookies to me first? Stranger HAD to be the first person in the store and buy the cookies. Nevermind the fact there were still tons of cookies to pick from; this guy just had to the the first customer of the day because…reasons. The baker explained he had no control over who came into the store and what they bought. He could make a separate batch and reserve the cookies if the customer was willing to pay. Of course this request was shot down. Customer angrily demanded the baker make sure no one touches the sugar cookies until he got there first. When the baker asked how he’d know what day the customer would stop in, he was met with more craziness.
As the stranger stormed out, I heard him mutter he’d “show” the jerk who stole “his” cookies first. Little did he know he was walking right past said person. I ordered my usual and listened to the baker air his grievances. Apparently this customer had lots of unreasonable demands, gave the baker a hard time whenever he stopped by, judged the baker’s lifestyle (he was gay) and was known for being a jerk to everyone in the shopping district. I was mad that this guy was mean to my friend.

A week came and passed.
I came into the bakery next week and jokingly asked if I was first customer of the day. Then we caught sight of him walking down the street from the window.
Before I could even think over a strategy, I asked to purchase all of the sugar cookies. Not 1, not 2, not 3 or 4. ALL. OF. THEM.
The baker asked if I could afford it and I could; I actually had some extra money from my birthday that week. The baker smirked and wrapped up my order, finishing just as the man entered the shop. The man glared at me, then looked at the empty cookie case. He looked shocked as he was used to getting his cookies even if he wasn’t first.
As I received my cookies, the baker explained I purchased all the cookies he had made that morning. And the shipment for dough ingredients wouldn’t arrive till that evening so there wouldn’t be cookies for another day. I started munching on a cookie as this man complained how it was “immoral” to allow me to purchase several dozen cookies and leave him with nothing (despite tons of other options in the store). The baker argued that I was a frequent customer and even if I wasn’t loyal to his shop, how could he turn down making a profit? After all, a bakery is still a business.
The stranger turned to me. I smiled gleefully and continued eating my cookie. He looked like he wanted to yell at me but the universe shined down on me. Some police officers entered the bakery to get snacks. No way was this guy going to harass me in front of them. And they settled at a table so they weren’t leaving any time soon, unlike the stranger who had to go back to work. The stranger grumbled some curses as he left.

I didn’t have any issues nor did I run into that guy. Actually, he didn’t even stop in on Saturday after that. Maybe he wised up and realized he’d get his wish if he visited any other day of the week.
I continued to be a loyal customer and order cookies no problem (sometimes discounted or given extras) until I graduated and moved. I still keep in touch with the baker sometimes.