Miracle on 34th Floor by Sophia Summers

What do you do when the man you’re falling for secretly works as Santa in a department store? Hire on as one of his elves.
VP of Marketing, Decker Kringle happens upon a conversation about shutting down Santa’s Visits at Gimbels, his favorite iconic department store in New York City. Without thinking, in order to save the store, he agrees to finish the night as Santa.
Joylin wants nothing more than for Decker Kringle to notice her. But why would he? He can’t see her tiny cubicle from his corner office. When she finds out he is filling in for Santa at Gimbels, she resorts to desperate measures to get his attention.
As Elf and Santa, the two navigate the pressures of their jobs at a huge firm as well as trying to save Santa at Gimbels while falling in love. Things heat up, when Decker walks by and sees his elf in the break room.