Pinkie Pie continued to work at Sugarcube Corner until the elder Cakes retired and Pound and Pumpkin took over, and Pinkie worked for them until they retired. When it came time for the grandchildren to take over they didn’t feel right being in charge because Pinkie had worked there longer than they'd been alive. It may have been their family's business but Pinkie was the rightful air as far as they were concerned. So Pinkie took over as the grandkids went off to pursue careers in new fields.
Pinkie lived and worked at the bakery, as well as continuing to be the party pony everypony knew. The lives of Pinkies eternal friends had taken them out of Ponyville at one time or another. It was when Pinkie was the only one living there that the Ghastly Mask returned.
When Luna had mysteriously disappeared the magic that bound the mask waned, which enabled it to escape and return to Ponyville. It believed it would be unopposed as the one who defeated it before was now gone.
The town was gripped with fear as the ponies were besieged by nightmarish phantoms and visions of their most terrible fears. The mask believed itself victorious until it realized there was still one pony who wasn't afraid, Pinkie Pie. The Ghastly Mask needed the entire town to be afraid for it’s power to be absolute.The Ghastly Mask confronted Pinkie at her home, but even face to face Pinkie was unafraid.
The Mask focused its anger and set Suger cube corner on fire, but even with her home ablaze Pinkie still wasn't scared. In fact she found the Mask’s outburst amusing. A slight giggle bubbled up in her throat and the body the Mask had manifested faltered almost imperceptibly, but Pinkie did perceive, and in an instant knew the Mask’s weakness. It was the same weakness all fears had, the one her grandmother taught to her long ago. With a big bright smile Pinkie let out a single “HA” and the Mask’s body began to crack revealing white light from within. The body then shattered and the mask fell to the ground where tendrils of black smoke emerged and disappeared into the sky.
When it was all over the only thing left was a flat piece of wood with eye holes cut out. Whatever evil magic that once powered the mask was now gone, taking with it the hideous shape it once had. It was done, the town was saved and the only casualty was The Sugarcube corner.
The citizens wouldn't stand for Pinkie being homeless, so they pulled together and built her a new home. They all worked tirelessly for a week, and what they ended up with was a small palace. It wasn't as big as Twilight’s castle but it was still bigger than any of the homes in Ponyville. Pinkie appreciated her new home, but there was no way she could keep a place so grand to herself. The small palace soon became the place where pinkie held the most important parties. Milestone birthdays, and anniversaries, as well weddings. Rarity herself was remarried there with Twilight performing the ceremony.