I always wanted to make PokeyPie offspring, but I never had proper idea for them XD But, now I'll give it a try:
Name: Marshall Royal Pierce(Marshmellow for practically everyone, what drives him mad)
Parents: Pinkie Pie and Pokey Pierce
Siblings: Twin brother- Pickaxe
Type: Earth Pony
Occupation: Baker
Personality: Mean, grumpy, sarcasstic, responsible
Marshmallow is a hardworking, busy colt with reluctance to other ponies. Ponies says that he used to be really cheerful kid in a duet of party planners with his twin brother, however Pickaxe found his new passion (mining) and moved out to a rock farm. Without his brother, Marshmallow became kinda lost, and having a "blank flank"didn't help him too much to get friends. And with constant companion of his too cheerful mother, he turned out to be a grumpy baker.
Despite his difficult character and how much she has been irritating him, Marshall loves his mother and tries to take care of her with her silly ideas. He's a very good baker but he hates when someones interrupts him.
Extra:
-He's afraid of dark, that's why he couldn't acompany his brother in mine.
-He's good at magic tricks.
-Can brake 4th wall like his mother.
-His parents from father's side lives in Canterlot.
-He loves his apron.