Pinkie Pie pondered over this particular perplexing pastry puzzle persistently.
Where had it come from? Who made it? Why did they make it? Why was it on the ground?
These questions buzzed around Pinkie's head as she walked through town, paying no attention to the citizens she bumped into.
"Hey! Watch it you clumsy- Oh. Hey, Pinkie. What's up?" This statement brought Pinkie back from her unresponsive stupor. She widened her eyes in surprise at the cyan pegasus in front of her, down on her knees in a mud puddle. The pegasus grinned, her eyes lit up with relief.
"Dashie?" Pinkie's voice raised in shock.
"Sorry I yelled, Pinks." Rainbow Dash stood and shook out her feathers. "It's just that I'm really stressed out about the Wonderbolts tryouts tomorrow. I have to rest my wings until then and you have no idea how many ponies bump into you on the ground." She thought back on that statement. "Well, maybe you do, being an earth pony and all. But there's almost nopony to bump into in the sky. Usually you can just fly right over them." Rainbow looked closer at the pink mare. "Are you okay, Pinkie Pie?"
"Yeah, why?"
"You've got applesauce in your mane."
Pinkie raised her eyebrows. She did? She struggled to look at her mane and after some effort (and some contortion) she saw the chunks of fruit stuck in her tangled hair. "Oh yeah! That must've been from when I crashed into the apple stand!" She shook her head vigorously and the apple chunks flew off, leaving her mane spotless.
Rainbow Dash was still confused. "Why did you crash into an apple stand? They're not very hard to avoid."
Pinkie eyes avoided the pegasus's gaze. "Well, I guess I was just the tiniest bit distracted..."
"By what?" Rainbow Dash was curious about what could've distracted the pink party pony so much that she comepletely ignored her surroundings.
"Well," Pinkie began, dragging out the word. "It all started when I was walking down the street..." She repeated the same story she told to Twilight, except with various tangents that Rainbow interrupted, trying to get to the point. "...And so now I have no idea what it is, where it came from, or who made it." After she finished her story she took in a deep breath, realizing that she had been talking so fast that she had forgotten to breath.
"Super-sweet cupcake, eh?" Rainbow Dash asked, mostly to herself.
"Well, I don't really know if it's a cupcake..." Pinkie corrected.
"Whatever," the pegasus dismissed. "Where is this thing? I wanna see how sweet it really is."
"Are you sure? I mean, even I thought it was too sweet, and I work at a bakery..."
"Don't care. Where is it?"
Pinkie thought that her friend could probably work on her manners, but didn't object. "Okay. If you insist," she said warily. "I left it at Twilight's."
"Well then let's go." Rainbow flew off in the direction of the library. Pinkie shrugged and bounced alongside her, prompting the pegasus to wonder how she managed to keep up with her. Her! The fastest young flyer in Equestria!
"Hey, Dashie!" Pinkie shouted up to her friend. "I thought you were supposed to rest your wings!"
"Oh, horsefeathers!" Rainbow cussed. She folded her wings in midair and fell to the ground. In her anticipation, she had forgotten that she wasn't supposed to fly. She felt grateful that she hadn't flown very far, or very high above the ground. She sighed. "C'mon, Pinkie," she called. "Let's walk to the library."
************
A short walk later, the two mares had arrived at the giant hollow tree that contained the town library. Pinkie Pie knocked on the door, calling her unicorn friend's name. After a few attempts and several minutes showing no promising results, Rainbow thrust out her strong back legs at the door, nearly ripping it off its hinges, shouting, "TWILIGHT SPARKLE, I KNOW YOU'RE IN THERE! PINKIE TOLD ME ABOUT THE CUPCAKE AND I WANT IN!"
Pinkie felt that Dashie could've been more polite and less dramatic about it, but decided not to mention it. Who was she, the element of laughter, to dampen somepony's fun?
The two mares trotted inside the large, hollow tree only to find their friend sitting in the kitchen and pouring the contents of a gallon of milk down her throat. Twilight turned towards the door, her cheeks still full of the beverage, and quickly swallowed. "Oh, hey guys," she chirped, somewhat shocked by the rainbow-maned pegasus's outburst. "Sorry I didn't come to the door. I was... preoccupied." The unicorn blushed sheepishly.
A gaping Rainbow Dash spoke first of the two visitors. "Why were you chugging milk?"
The blush on Twilight's cheeks reddened. "Oh, well, I took a small bite of the cupcake and it was very sweet." She motioned towards the refrigerator. "I was almost out of milk after the taste was refreshed and I bought in bulk in case I wanted to experiment..." She finished, chuckling. "Good thing, too. Turns out there's an aftertaste..."
Rainbow rolled her eyes. "Oh, please," she chided. "It can't possibly be that sweet." She trotted over to the cupcake on the counter and chomped off about a fourth of the rich desert.
Both Twilight and Pinkie widened their eyes and exclaimed simultaneously, "Rainbow! Don't!"
The warning too late, the pegasus gulped down the bite and smacked her lips. A moment later she pressed her tongue against the roof of her mouth, relieving it to shout, "MILK! I NEED MILK!" She then dashed to the kitchen, and sounds of several gulps reached the ears of the pink earth pony and the purple unicorn.
Twilight sighed. "I tried to warn her..." she muttered to herself, half amused by the stubborn pegasus.
Pinkie was a bit more forlorn, and looked at her half-eaten cupcake with worried eyes. "Twilight?" she called to the unicorn. "Can you make some replicas of the cupcake? For testing, I mean." Her tone let on more than she was telling, but Twilight didn't question it.
"Well, I can't use magic to create a perfect replica, if that's what you mean," she replied. "However, I may have a book that can help recreate it the old fashion way." She trotted over to one of the shelves in the library, until she pulled out a good-sized textbook with a green cover and navy blue letters spelling out Reverse Engineering: How to Engineer the Mysterious by Reversing the Process. The unicorn flipped some pages before getting to her desired chapter. "Ah, here we go!" she exclaimed with enthusiasm. "Good Eats, But How Are They Made? This chapter details how to reverse engineer a recipe." After a short look-through she said, "It looks fairly simple. First, we taste the product while seeing which ingredients could be used. Then we just organize the ingredients into feasible recipes, trying out various amounts and orders of the ingredients until we get our desired result."
Pinkie Pie lit up. "Ooh! We can use Sugarcube Corner to collect ingredients and bake recipes!"
"Are you sure the Cakes won't mind?" Twilight asked.
"They're out of town for a few days. They decided to take Pound and Pumpkin to Ocean Land. They also closed the bakery till they return and told me I could still use it if I liked!"
The trip was convenient, considering the circumstances, and it appealed to Twilight. "Okay, then. Let's do it!"
As they made for the bakery, Rainbow Dash hopped up. "I'll bring milk!"
************
After arriving at Sugarcube Corner, the three mares set up shop. Twilight put down the book and cupcake, which were previously being levitated along by her magic. Pinkie hopped around, preheating the ovens and opening cabinets filled with ingredients and cooking utensils. Rainbow put the several gallons of milk she dragged along into the refrigerator, getting the feeling that they would need it.
Twilight used her duplication spell to split the cupcake into two, then four, then eight, and on and on until they had a good sized pile of cupcakes on a large platter. "All right, Pinkie," she announced. "Let's start tasting!"
The unicorn levitated two cupcakes to Pinkie and herself and they both took a long, savoring bite. A moment later they began shouting out ingredients.
"Chocolate!"
"Sugar!"
"Milk!"
"Flour!"
"Oil!"
"Oil?"
"Yeah! Veggie oil!"
"Okay then. Oil."
This went on for a while, with ingredients being shouted out and occasionally vetoed, while Rainbow Dash poured glasses of milk for her friends and wrote down the accepted guesses in a notebook. Soon, the three mares felt they had the correct ingredients (as far as they could tell) and decided to formulate recipes. The amount of ingredients, order of adding the ingredients, and methods of preparing the ingredients all varied, which meant that Twilight and Pinkie had quite a few cupcakes to make.
The baking and tasting of the cupcakes was often disastrous. Most of the recipes were inedible, causing Twilight and Pinkie to take several trips to the little filly's room to evacuate their stomachs. Several cupcakes weren't even tasted. They were so obviously not edible that they went directly to the oven to the trash. Rainbow sat on the sidelines, watching with barely restrained laughter.
"Oh sweet Celestia!" she exclaimed at one point. "These are worse than the 'baked bads' incident!"
Pinkie cringed. The memory still nauseated her.
After a few hours, the group had gone through all of the recipes and were choosing the ones most like the original. "Okay," Twilight reviewed. "It seems as though number forty-two was the best so far, but it still seems to be missing something..."
Deep in thought, the mares sat silently. Suddenly, Pinkie Pie sprang up, gasping, and sped off to the nearest cabinet shouting, "Chemicals!"
Twilight was shocked. "Chemicals? What do you mean?"
Pinkie explained as she rooted through the cupboard. "Mr. and Mrs. Cake always use chemicals in their more popular snacks. Something about tasting better... or lasting longer... or color... Anyway, they keep it all in here!"
Twilight wasn't convinced. "Are you absolutely sure? I work with chemicals all the time and they can be dangerous..."
"It's okay, Twilight! These must be edible chemicals." Pinkie carried bottle after bottle over to her friends. "Let's test 'em out!"
This process was less nauseating than the last one. Most of the chemicals were tasteless, affecting only the color, or made little difference.
Pinkie started adding chemicals at random after a while, convinced that they would come across the correct recipe sooner or later. "Red dye number forty! Titanium Dioxide! High fructose corn syrup! Agar! Xanthan gum! Lactic acid!" On and on she went, often accompanied with twitches and vibrations from parts of her body.
Eventually, by some amount of severe luck (and some Pinkie senses) they finally had the perfect replication of the mysterious cupcake.
"Girls," Rainbow Dash announced, "we got ourselves a cupcake!"