Toyland: The Legacy of Wallace Noel — Tony Bertauski

The 7th standalone novel in the Claus Universe.

If you want to play, and stay out all day, I know the place where we can do it.

Great aunt Annie was a storyteller.

It was mostly Christmas stories she told. No one had ever heard her tales about giant reindeer, living snowmen, and Santa Claus. There were no movies about them. No books. When she passed, everyone thought they'd never hear such stories again.

But she saved the best for last.

When Tin's family inherits an enormous rural estate, they discover the hidden treasures of Toyland. The eccentric mansion was built long ago by a toy magnate named Wallace Noel, a man made famous by his beloved Noel toys.
Tin and her family spend Christmas at Toyland and find abandoned workshops, old photos, and forgotten toys in strange rooms. 

When Tin discovers an authentic-looking elf hat, everything changes. She comes to know the truth behind the urban legends of Wallace Noel and what made his toys so special.

And where Great aunt Annie got her stories.