Pinkamena is actually Pinkie Pie when she's depressed or sad. In the show My Little Pony, she's depicted a few times, such as "Party of One" Episode 25, where Pinkie Pie tries to have another party for Gummi, her pet alligator, but no one wants to go and she starts reverting to her old self.
In episode 23 in, "The Cutie Mark Chronicles" it tells the tale of her being born on a rock farm and how her life was boring and below normal. Her hair was straight in there and her full name is used for the first time. Which is, "Pinkamena Diane Pie."
But she's known as Pinkie Pie for short :3
I think this is what you were asking, but she does have a few pasta's about her too, as you already have seen :3
She is pseudo-cannon. and there are a plethora of fan-fics' or stories if you will that have her as the main character the most well known one by a landslide is "Cupcakes" by Sergeant Sprinkles. (Fun fact Sergeant Sprinkles is a founding member of the Facebook-esc site for bronies Cloudsdale and he is nothing like what you think he would be judging by "Cupcakes")