The Christmas Deal by Keira Andrews (and a bunch of her other holiday books too!)
One More Yule Log by Julia Talbot
Hometown Christmas by Garrett Leigh
The Winter Spirit by Indra Vaughn
Holiday Outing by Astrid Amara
Lone Star by Josh Lanyon (also Icecapade)
Merry Christmas, Mr Miggles by Eli Easton
North Pole City Tales series by Charlie Cochet
Love Around the Corner by Sally Malcolm
Holly and Oak by R Cooper
Wrapped Together by Annabeth Albert
I'm absolutely positive I'm going to start kicking myself for not listing so many other books as soon as I post this (because there are so many good ones!), but that's a few anyway.
I haven't written a holiday romance yet, but if you're looking for a warm and cozy fantasy romance set during fall/winter/winter holidays, try The Merchant's Love. It's a warm hug of a book in which a bookish royal and the merchant awkwardly, endearingly besotted with him fall in love over books and baked goods.
Happy reading, all!