The Christmas Countdown by Holly Cassidy

From the author of The Christmas Wager comes a charming holiday rom com about a young, recently heartbroken woman who is tasked by her sister to complete Advent calendar challenges in the lead up to Christmas to reignite her belief in herself, the holidays, and love again.

She’s given up on love and Christmas… but fate has other plans.

All Callie wants for Christmas is to hibernate. She’s still reeling from being dumped by her childhood sweetheart, and under no circumstances will she go home for the holidays considering her ex will be right next door with his new, perfect partner. Callie is officially in grinch mode, but her meddling sister, Anita, won’t let her give up on life, love, and Christmas quite so easily.
Anita stages a Christmas intervention for Callie with a homemade Advent calendar challenge—cheerful tasks to push Callie out of her comfort zone and into the holiday spirit, inspired by a childhood tradition. Callie reluctantly plays along, but when she comes face-to-face with a charming baker who just might be the spoonful of sugar she needs, her strict rules on love and the holidays are tested. As they strike a deal to do the activities together, could the twenty four little doors on Callie’s Advent calendar not only open up one, but two closed-off hearts?